Remember that quoted $1200 is of course total value – not the affiliate share.
We keep stats on all our partners, measure stats by month, and by click, and by FTD. Even averaging over annual periods we see a wide variance between partners and periods, not surprising as MuffinCrumbs has indicated a whale can really inflate the average.
However, over sports we see number that suggest “average” total player value can be between $500 to $2500, and casino $600 to $1500 … so that $1200 average number does seem to fit our data.
As for player lifetime … I’d suggest that typical player “half-life” is something like 1 month, 3 months, 6 months, 1 year, forever !!
So 50% only play for the first month, and another 25% drop out over 3 months, 12% more are gone after 6 months (87% total gone now), and another 6% are gone in a year. The good news is that if you keep a player active at a site for a year (around 7%) then they seem to last indefinitely.

Obviously the long term players are the ones that really boost the player averages. while many of the short term ones are small depositors (say $20 to $50) that try it and do not like it enough to stay. Of course there’s still lots of variation – every now and then you get a short term “whale” that plays and loses big. It really depends on your site, your reader base, and the quality of the program that you sent them to.