Don't pay for it. There are only 3 search engines (Google, Yahoo, Bing) worth paying to be in for most advertisers and two are about to consolidate. Even among those three it's often not worth advertising in any but Google for most people.
And you should learn to check the traffic yourself on sites like Alexa. You'd see that it's about as used as able2know, which is well under the scale you need for most search advertising.
P.S. they really are just repackaging someone else's results in an unusable way, and as such aren't really a search engine themselves.