Yahoo! Search Marketing publish a blog with tips and advice on getting the most out of their (relatively) new PPC advertising system. One of the more recent additions to the blog is an explanation of the Quality Index which was introduced over the past few months and is a thinly veiled copy of Google's Quality Score system.

The Yahoo! Quality Index works in much the same way, whereby advertisers can benefit from higher ranking positions and/or lower costs per click if their adverts are more relevant - meaning that more people click on them and, of course, make more money for Yahoo!, as well as the advertiser, hopefully!

This entry offers a good summary of the Quality Index system and things to do in order to improve the graded scale against each advert. Also related to the whole issue of relevancy and increasing clickthrough rates, Yahoo! have also published an entry on how to improve your advert's copy by using their new tool that displays up to 6 relevant ads for each keyword to see what others are doing and therefore helping you make your own advert stand out from the crowd.