Big numbers for The First Dance.
Brandon Thurston of Wrestlenomics reports AEW Rampage on August 20 drew 1.129 million viewers with a 0.53 rating (692,000 viewers) in the 18 to 49 demographic. The demographic number tops every episode of AEW Dynamite outside of the debut episode on October 2, 2019, which drew a 0.68 in the demo.
The opening segment with CM Punk drew 1,341,000 viewers on average and a 0.65 rating (842,000 viewers) in 18 to 49.
For comparison, the final number for WWE SmackDown on Fox came in at 2.102 viewers with a 0.57 rating (738,000 viewers) in the 18 to 49 demographic.
The premiere episode of AEW Rampage on August 13 drew 740,000 viewers with a 0.31 rating (396,000 viewers) in the 18 to 49 demographic.
Though CM Punk's debut was never made official or advertised, it was strongly hinted at and teased by AEW leading up to the show.
According to John Pollock of POST Wrestling, AEW Rampage averaged 107,900 viewers and 75,000 in the 25-54 demographic on TSN 2 in Canada. The show aired on a one-hour delay, but did air live on the TSN Direct streaming service. No numbers were available for TSN Direct.
On YouTube, CM Punk pulled big numbers with his entrance sitting at 5.5 million views and his promo at 4 million views.
You can keep up with all the television viewership numbers in wrestling with Fightful's resources section.