Hey tryme, yes, there were enough people playing when I tried it, the 75 ball room had around 40-50 players, the 90 ball room had a bit more, 50-60, so I think the perfect number to have a chance to win and not being overcowded (I saw once 300 players at Jackpotjoy in one room lol). I guess when there will be more people they will open up another rooms, so Affiliate Arena’s bingo rooms are definitely not empty 
I suggest you to sign up with each bingo you promote as a player, if you want fresh promotions for your site you will get if firsthand, the affiliate sides are sometimes slower at the programs lol in case of newsletters – players will definitely get it.
I agree there is a lot of potential with Affiliate Arena’s bingo sites, I really love the look of them (I always had the feeling that sites targeting UK looks really kool, but sites targeting the US have a lot of ugly looking amongst them – at last something from the same quality for US players.
Anyone else promoting Affiliate Arena and has some experience?