I noticed few days back that Google has two different tools for counting the backlinks to your website:
1. (type the word link+: and then without any space after the colon type the address of your website starting with www
2. another tools is the one from the account Google Webmaster Tools
For the same website, the first tool shows only a few backlinks in comparison with the second tool. What I've concluded that never ever use the first tool for finding your backlinks or your competition's backlinks. It's not good at all, believe me.