Full disclosure: I frequent private "blackhat" forums and although I do not participate in these activities, I blog about them anonymously. Furthermore, I know a few people (online) who do stuff similar to this with CPA content lockers, so I'll try and give you an educated guess. In general the average conversion rate in the TV show/live content is around 0.5-3% depending on the quality of traffic.

Now, as you can see from Google Trends[1] some of these get very popular and trend once pretty much every year. In the second comparison, I've compared the search terms with a term I know is definitely popular to get relative popularity of the terms [2]. Comparing these two terms I can get an idea of the amount of traffic these website would get in the time period. I would estimate that the "big spammers" would easily get around 250k-500k uniques from multiple sources (spamming, mass advertising, social media, botnets etc).

Assuming they get paid $2 every signup, and have a conversion rate of 1.5% with 300k uniques, it would bank them around $9k, of course I'm only talking about the big guys here who have done this for a long time.

In general, I would say that the following is correct:

Upper quartile average: $1-3k per day for a few days

Lower quartile average: $50-60 per day for a few days

Quick edit: It should also be noted that for these live games over 95% of the traffic will be from the USA hence the large profits.

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[1]http://www.google.com/trends/explore#q=Iowa%20vs%20Michigan%...

[2]http://www.google.com/trends/explore#q=Iowa%20vs%20Michigan%...