Not really, some third party sites might be running search engines that only return overture results full stop so 18th position may just be a normal web browser surfing what he sees is the second page of results.
You have to remember that as all listings in overture are added by people or are targetting content that they relate to most often the results will actually be self policed into being probably more reliable that even little G's results for the same terms sometimes.
Like all traffic you weigh it up on a keyword for keyword basis, decent tracking will tell you if the users coming to your site are real or not just from average behaviour. Ie not cliking on more than then link to come to your site etc etc.
Having said all that i wouldnt of thought the quality of traffic from someone clicking on the 18th page would be that great if they didnt like what was 17 places above it already. You do have to consider the spam sites though that might use overture results on their pages and then get indexed by google as well. So even in that case it might of been the first result the customer actually saw and because it is the 18th result its not like there is going to be too many sites that show the listing so it wont get so clobbered for duplicate content eh ;-)
LinkBack URL
About LinkBacks

Bookmarks