Yahoo site explorer is the best tool to use to find incoming links to your site, and without them SEO’s would not know much about the strategic link building practices of their associates.
Recently yahoo started showing erratic backlink results and caused much speculation in the SEO world that they were on the verge of removing this research tool as Google and MSN have done. Google has the most reliable link data, but it is hidden behind Google Webmaster Central, disabling competitive link research on websites you don’t own. MSN is a mixed bag, some seeks they show relevant link data, other times you might as well ask the magic 8 ball for a backlink count. For the past few years, showing links was Yahoo’s game to loose.
While the counts have been incorrect in some cases, the actual returned results have been correct. However, we did roll out a product fix yesterday and will be rolling out a couple more over the next few days to resolve this difference in counts some of you have observed.
If you are serious about getting a better ranking for your site and engaging in link building, Yahoo Site Explorer is the tool you need to monitor your backlink status.