Are the results supposed to be the same when I type link:<mysite> in Google or use the Webmaster tools to examine my external and internal links? They certainly aren't for me. The last two yield values that are, respectively, 50 and 30 times larger than the first. Apparently, Google is using different systems and/or methods are being used in the computations. But if the Webmaster tools are the more accurate, doesn't this imply that link:<mycompetitors'site> is going to yield essentially useless information about the number of backlinks that my competition has? If using link:<mysite> and queries of the external links in Webmaster tools are SUPPOSED to produce different values, can someone point me to the Google URLs that differentiate them?
Google doesn't want you to see your competitor's exactly link profile. Yahoo let's you see first 1000 backlinks for any site. But google will just dump a sample of backlink profile. You might want to just search for their domain name and get more results.