Here’s some more interesting information about backlinking …
As of February 2007, Google introduced a new facility as part of their Webmaster Tools to assist with backward link checking. The tool lists all of the incoming links to your website and allows you to see how many are linking in to a specific page on your website.
Refer to an official Google blog entitled discover your links for more information, including this interesting excerpt (I’ve bolded the really interesting bit):
We do limit the amount of data you can download for each type of link (for instance, you can currently download up to one million external links). Google knows about more links than the total we show, but the overall fraction of links we show [in Google Webmaster Tools] is much, much larger than the link: command currently offers. Why not visit us at Webmaster Central and explore the links for your site?
Posted by Mark Read 
