BidVertiser is another contextual advertising program, similar to Google AdSense/AdWords where you get paid from clickthroughs of ads placed on your site. It also includes a referral program, where you can earn from referring publishers or advertisers to the program.
Minimum payout threshold is $10 through PayPal, or $50 by cheque. I haven’t yet used this program anywhere, as you can’t use a program similar to AdSense on any site running it (I checked, Google’s ToS seemed to only restrict it by page). I’ll decide which site to use it on, or maybe create a new one.