Stay away from Yahoo with a 100 foot pole.
An Advertiser last year HAD "Make Money With Yahoo" offers. Clickbooth carried the ad. We mailed it for 30 days, it rocked, then I got a phonecall from a Yahoo attorney.
They were literally contacting every pub who did them via email, especially if you were hitting the Yahoo inbox, and giving a verbal C&D (cease or get dicked). They then contacted the Advertiser and the offer was pulled within 48 hours I believe.
You'll notice no new Yahoo offers exist... it's ashame because the Yahoo offer had an enormous EPC for email, and was one of our best offers ever.
I agree it sounds silly to mail a Yahoo offer on the Yahoo network, but it wasnt converting as well on other domains, and we thought the offer was legit since Clickbooth carried it...