Cardplayer is, admittedly, a special case as they go beyond the scope of affiliation. But their forums have over 40k members. That is huge compared to other sites like 2+2, whose forums have ~4k. With 40k registered members, you can imagine the amount of unique visitors. Doesn’t take a high convertion ratio to come up with huge affiliate revenues.
Work on one very large site, or on 10 mid-sized ones?
That’s the source of my question.