I do a simliar thing where i signup for each sponsor with a specific email address,
[email protected], i keep track of it all in my aliases file.
Too biggest offenders of late:
Rookie Babes (about 20 a day and as high as 45 a day)
Nasty Dollars (about 10 a day - started two days ago)
I pulled all my traffic to rookie babes about 6 months ago when they started this shit. I'm thining about pulling my traffic from nastydollars too.
The emails are simliar to those posted above.