I can confirm that World Bingo affiliates pay every month. They used to pay right at the beginning of the month and now pay about half way though.
I haven’t been with them that long – I have about 169 acquisitions in total. My impression is that the conversion rates are good. Player value is good. Short term retention seems better than most. It seems like long term retention could be improved – but we’ll see in a couple years. I find that all of the sites perform equally well.
St Minver has performed terribly for me and I sent them alot of highly focused traffic with nothing to show for it.