Where the SEC Championship Crowd Actually Went

How Placecast Hotspot Detection Works

Hexagon Density at a 200-Person Privacy Floor

Placecast aggregates device-level visitation into uniform hexagons of approximately 0.6 acres (26,000 square feet). For this pilot, Motionworks isolated the cohort of devices observed inside Mercedes-Benz Stadium on December 1, 2018, then traced that same cohort's activity across the three-day window. A hexagon only reports as a hotspot when more than 200 individuals are observed within it during a 15-minute interval - the floor that protects individual privacy.

What Each Hexagon Captures

Approximately 0.6 acres / 26,000 square feet per hex
Roughly 30 hexes fit inside Mercedes-Benz Stadium (18 acres)
Hotspot threshold: 200+ people in a 15-minute window
Each hex reports a center latitude / longitude for mapping
Time-keyed at 15-minute intervals across the full window
Estimated attendee count per hex per interval
Same device cohort traced across all three days
Coverage extended wherever the cohort traveled

Pipeline for the SEC Championship Pilot

Motionworks isolated devices observed inside Mercedes-Benz Stadium on December 1, 2018 - approximately 114,000 individuals (vs. 77,000 official attendance, since the cohort includes staff and vendors)

The same cohort was traced across November 30 through December 2 and binned into 0.6-acre hexagons at 15-minute resolution

Hexes meeting the 200-person privacy floor were exported with center coordinates, attendee counts, and timestamps - ready for Tableau, GIS, or member-CRM matching

The same Placecast pipeline runs continuously across every U.S. DMA - the SEC Championship pilot is one configuration of a system that powers ongoing visitor analytics at any place-set, on any window, for any cohort.

Slice 01 - The Kickoff Window

39 Hotspots, 89,800 Estimated Attendees, in 15 Minutes

At kickoff (4:15 PM to 4:30 PM on December 1, 2018), Placecast flagged 39 active hotspots concentrated in and around Mercedes-Benz Stadium. The estimated population per hex ranged from the 200-person privacy floor up to 19,500 in the densest single hex. Some individuals are necessarily counted in more than one hex as they moved through the stadium during the interval - the sum is therefore an upper bound on distinct attendees, not a count.

Active Hotspots

all within or adjacent to MBS

89,800

Estimated Sum

across all 39 hexes (with double-count)

19,500

Densest Hex

single hex peak inside MBS

200

Floor

privacy threshold per hex

Placecast surfaced 39 active hotspots in a single 15-minute kickoff window - all within or adjacent to MBS.

Estimated population summed to ~89,800 across the 39 hexes during the 4:15-4:30 PM window, ranging from the 200-person privacy floor up to 19,500 inside the densest hex. The cohort total of ~114,000 devices through MBS on the day exceeded the 77,000 official attendance because Placecast captures staff, vendors, broadcast, security - not only ticketed attendees.

Cohort vs. Attendance

Cohort size: Motionworks observed approximately 114,000 individual devices through Mercedes-Benz Stadium on December 1, 2018. The officially reported attendance was roughly 77,000. The gap is staff, vendors, security, broadcast crew, and pre / post-game traffic in the concourse - not double-counted attendees.

Slice 02 - The Citywide Footprint

473 Unique Hotspots Across Three States

Across the full three-day window, the same MBS-attendee cohort produced 473 unique hotspots. Coverage spanned Tuscaloosa (the University of Alabama), Athens (the University of Georgia), and every major district of Atlanta. The geographic spread is itself the first product of a Placecast study - it is what tells a bureau where its visitors actually were when they were not at the venue.

Tuscaloosa, AL

RoleUniversity of Alabama

DetailOrigin cohort - Crimson Tide

Athens, GA

RoleUniversity of Georgia

DetailOrigin cohort - Bulldogs

Metro Atlanta

RoleBulk of activity

DetailBuckhead, Midtown, Downtown, Cobb

473

Across three days the cohort generated 473 unique hotspots spanning Tuscaloosa, Athens, and metro Atlanta.

The geographic spread is itself the first deliverable. A bureau that stops at "77,000 attended" never sees that the same cohort was at a hotel bar in Buckhead at 1 AM, a steakhouse in Midtown at 8 PM, and a MARTA platform on egress - all of which are addressable in member services and sponsorship sales. Placecast turns the attendee list into an itinerary.

Hotspot Volume by Day - The Game-Day Spike

Hotspot count peaked in the hours just before and after kickoff and dropped to near-zero overnight and on shoulder days. The post-game spike in hex count tracks an equivalent spike in estimated population - large clusters moving rapidly between hexes inflate counts as the same individual passes through several hexes within a 15-minute window. The narrow nightly base reflects the privacy floor: when density falls below 200 per hex per 15 minutes, the hex stops reporting.

Slice 03 - Hotel Density After Hours

The Westin Peachtree Plaza - The Lone All-Night Hex

Most major Atlanta hotels register hotspots through the early evening of game day and again in the morning. The Westin Peachtree Plaza is the only hotel that registers a hotspot through the entire overnight - a function of its vertically concentrated room layout, where rooms stack within the privacy radius of a single hex. Hyatt Regency and Marriott Marquis spread their rooms across a larger horizontal footprint offset from their atrium bars, which keeps per-hex density below the 200-person floor overnight.

Hourly Average Estimated Attendees - The Westin Peachtree Plaza

Hourly average of 15-minute interval estimates inside the Westin Peachtree Plaza hex across the three-day window. Zero indicates the hex did not register a hotspot for that hour - density fell below the 200-person privacy floor.

Westin Peachtree Plaza - hourly average

Game kickoff (4 PM Dec 1)

Hotel

The Westin Peachtree Plaza was the only hotel registering a hotspot through the full overnight on December 1.

Hyatt Regency, Marriott Marquis, and the Hilton register late evening and morning but disappear in the deep overnight. The Westin's vertical room concentration keeps density above the 200-person floor inside a single hex; the Hyatt and Marriott spread rooms across a footprint offset from their atrium bars, which dilutes hex density. The hotel-layout signal is operational - Placecast hex resolution interacts with building geometry.

Slice 04 - Matching Hotspots to Members

880 Members. 473 Hotspots. 40 Match Points.

ACVB exported its active dues-paying and civic membership directory on November 27, 2019 - 939 names. Geocoding returned 880 with confidence between 0.7 and 1.0. Rounding member coordinates to three decimal places (the resolution at which Placecast hexes naturally cluster) collapsed those into 639 unique addresses. Rounding the 473 hotspots to the same resolution collapsed them to 225 distinct cells. Of those 225, 40 cells matched at least one member - and those 40 cells contained 129 individual members.

Members on directory

939

Geocoded (0.7-1.0 confidence)

880

Unique 6-decimal addresses

700

Unique 3-decimal addresses

639

Distinct hotspots (3-decimal)

225

Hotspots matched to members

Members at matched hotspots

129

Why rounding matters: 6-decimal latitude/longitude resolves to roughly 11 cm. At that resolution, two members in the same office tower do not match the same hex. Rounding to 3 decimals (~110 m) aligns the directory to Placecast's natural hex resolution and collapses an entire stadium from 30 hexes to 6 - making member-to-hotspot matching tractable.

40 / 225

ACVB's directory matched 40 of 225 distinct hotspots - covering 129 active members.

The 939-member directory geocoded to 880 valid points (0.7-1.0 confidence), which collapsed to 639 unique 3-decimal addresses. At that resolution, 40 hexes hit a member venue - confirming members were doing real weekend work. The unmatched 185 hexes split into traffic congestion (Northside Drive, North Avenue) and venue-grade prospects.

Slice 05 - The Buckhead Discovery

Two Non-Member Nightlife Clusters Surface

Counting how many 15-minute intervals each hotspot reported - rather than just whether it ever reported - separates real centers of activity from temporary congestion. That count surfaced two distinct Buckhead clusters of high-frequency, non-member venues, plus a smaller pair tied to the Lindbergh MARTA station and three points where existing member hotels narrowly missed the match because their coordinates rounded across a hex boundary.

Area A

Big Sky Buckhead

Five Paces Inn

Member statusProspect - Cold (in CRM)

Hexes3 hexes (rounded) / 4 (raw)

Active window11 PM to 2 AM, both nights

Peak density~800 attendees at the busiest hex

Big Sky Buckhead was already named on Atlanta's published "5 Best Places to Watch the Georgia Bulldogs" list for 2018.

Area B

The IVY Buckhead

Tin Lizzy Cantina, Hal's The Steakhouse

Member statusNot in Simpleview

Hexes4 hexes (rounded) / 5 (raw)

Active window12 AM to 2 AM (IVY); 8 PM to 10 PM (Tin Lizzy / Hal's)

Peak densitySustained late-night density both nights

The IVY Buckhead was #2 on the same "top 5 places to watch UGA" list. Adjacent hexes also fired earlier in the evening.

Area D

Westin Buckhead, Embassy Suites Buckhead, Bones Restaurant

All near-miss matches against existing membership

Member status1 of 3 already a member; 2 missed by rounding

Hexes3 hexes

Active window9 PM to 10 PM, one of the two nights

Peak densityLower frequency - real venue, light night

Both hotels should have matched the membership directory. The Embassy Suites missed because its address rounded to a different hex than the hotspot center - a coordinate-rounding artifact, not a venue absence.

Two Buckhead non-member nightlife clusters - Big Sky Buckhead and The IVY Buckhead - surface as immediate prospect targets.

Both clusters fired persistently from 11 PM to 2 AM on both nights, with peaks near 800 attendees in the busiest hex. Both venues already appeared on Atlanta's published "5 best places to watch UGA" list. Big Sky was Prospect-Cold in ACVB's CRM at the time of the analysis. The IVY was not in Simpleview at all.

Area C - Lindbergh MARTA

Two adjacent hexes at the Lindbergh Center MARTA station registered hotspots only between 8 PM and 9 PM on December 1. Consistent with transit egress, not a destination - the cluster is real but the venue is the platform itself.

Arthur M. Blank Foundation

A single hex registered briefly at 8:45 PM on December 1 with approximately 500 game attendees, immediately outside the Arthur M. Blank Foundation in West Buckhead. Pattern is consistent with a private hosted reception that evening.

Midtown - traffic vs. venue

Midtown produced fewer recurring hotspots than Buckhead. The standouts: Piedmont Driving Club (1:45 PM Dec 1), Taco Mac (1-2 PM Dec 1; #5 on the UGA-watching list), and Renaissance Atlanta Midtown (1:45 AM Dec 2). Most other Midtown hexes traced to traffic congestion, not venues.

Outer-ring activity

Notable hotspots beyond the core: Renaissance Atlanta Waverly at the Cobb Galleria Centre, a westside warehouse (Ballard Designs?) likely registered by event-staff vehicles, and several MARTA stations registering on egress windows.

Why This Matters for Bureaus

Bureau membership grows by surfacing the venues that visitors actually use - not the venues that fill out a directory form. Placecast turns a marquee event into a citywide audit: which member venues earned the visit, which non-member venues earned the visit, and which hexes are just traffic. The output is directly actionable for member services, sponsorship sales, and bureau-funded co-marketing.

The Punchline

The SEC Championship pilot delivered 39 active hotspots inside a 15-minute kickoff window, 473 unique hotspots across three days, 40 matched members, and a clean shortlist of two non-member nightlife venues. All of it from the same Placecast workflow we run continuously across every U.S. DMA - hexagon density at the 200-person privacy floor, traced across any cohort and any window.

Operational Notes - What the Pilot Suggested Changing

Lower the privacy floor from 200 to 100 to surface lower-density venues. Move the interval from 15 minutes to 60 minutes to smooth nightly density. Add columns for dwell time, occupancy, and trip count to enrich each hex. Bundle hex centers into venue-level regions for cleaner CRM matching. Run separate analyses on place-sets (e.g., all Atlanta hotels) to estimate citywide hotel population on any given night.