SEO Tip #15: What’s the preferred way to check for links to my site?
Matt Cutts: The “link:” operator is accurate. It only shows you a sub-sample of your links. My preferred way would be to log-in to Google Webmaster’s Tools and we will show you a very exhaustive list of all your backlinks, pretty much all the backlinks that we know of in Google’s Webmaster console.
The nice thing is other people can’t spy on that, so your competitor can’t look at your backlinks. You can start to see some backlinks for other sites, Yahoo! Site Explorer for example, if you type in a URL into Yahoo Site Explorer, just their search box, you can explore backlinks a little bit that way.
So those are a couple tools that you can use. But, again it’s not that “link:” shows wrong links, it’s just that we don’t show all of the links that we know of. So there are a lot of different options that you have to find out more about backlinks for different websites.