with the only difference that Yahoo! has at least a quality scoring and smart-bidding system in place while Ask send tons of crap from search partners to his advertisers while selling all ask.com searches to google
Ask is crap. I have an ongoing dispute with them for $1,000 in click fraud. Long story, is I copied campaigns from G/Y/M that were converting. Ask traffic quadrupled no conversions, and analytics / log files didn't show this traffic even hitting my pages.
I haven't posted in awhile. But I tried ask.com about 2 years ago, and like the people above realized they have the worst traffic I have ever tried outside of goclick. After a test of $400, I ended up with 0 conversions and a 0.25% CTR on my landing page. I later decided to give it another try with some arbitrage.... again piss poor traffic. 7search >>>> ask.com.