I must say, I'm impressed with Ask.com's support folks. I bought 183 clicks from ask on a very competitive keyword. And the average user that came from their network of sites viewed exactly 1.0 pages. Not 1.06 pages, not 1.3 pages, 1.0 pages. During the same time period, the rest of the traffic that came to the site averaged more than 3 pageviews per user.
If you know anything about buying traffic from second tier sources, you know what this means: click fraud. (Someone set up a site, displayed my ads on their site, and then had a bot click on the ad. They got paid, Ask got paid, I lost money.)
Now, this is not a post about the evils of click fraud. As John Battelle would say, it's simply a tax, and if you want to play this game you pay the tax.
But Ask did the right thing when I complained. They researched it, they blocked traffic from that site, they refunded my money and they called me to explain the situation.
The most interesting lesson learned? If you want your ads to appear on Ask.com for competitive terms, buy AdWords ads. Ask backfills their own search results with AdWords. Think about that for a second.