link:example.com- if you use link operator (in Google) for your website to check backlinks and believe that whatever results shown are accurate you are probably mistaken. This was probably never a good way to check backlinks, but most of us have relied on this method since the time we learned the basics of SEO.
Though I am little late in updating you on this, but I felt this post will still help a lot more webmasters who still believe using link operator they would measure the actual popularity of the website.
Matt Cutts in one his video has updated that Google actually not emphasize much on this functionality and rather discourage this practice so to prevent spammer to gauge the actual strength of backlinks your site has. He says spammers and competitors may spy on the backlinks you have using reverse engineering and exactly knowing what sites are linking in to your site.
He agrees that the number of links displayed using link operator are relatively a small percentage of the actual number of backlinks your site has.
Matt Cutts suggests to login to webmaster account and check the actual number of backlink Google knows about your site.
Check out the video to know more on link operator and should link operator will give you the correct result of sites linking back to you.