It's worth noting that WWE did not announce an attendance number for Sunday's Evolution pay-per-view from the Nassau Coliseum on Long Island, NY. Michael Cole and Renee Young noted during the Kickoff pre-show and the main broadcast that the event was sold out but they never announced the number of fans in attendance, which they always do when announcing a sell out.
Our own Glenn Rubenstein was in attendance for Evolution and noted that the hard camera side was around 75-80% full with the rest of the arena being around 90% full. It was speculated on social media that WWE dimmed the lights in the arena to hide some of the empty seats.
It was believed that Evolution would be legitimately sold out on the day of the event. There was a surge in ticket sales following the announcement of Nikki Bella vs. RAW Women's Champion Ronda Rousey but tickets were still available on Ticketmaster as of Sunday morning. WWE reportedly sold 7,000 tickets before the Bella vs. Rousey announcement but around 3,000 of those tickets were sold to scalpers. Scalpers started unloading their tickets on the secondary market this past week, with some going for as low as $8 and $9.
You can see some of the crowd shots below, with another estimate of the crowd being at 65%: