People talking about deep linking, well I don't honestly see it a lot, but it's definitely very powerful, when you can understand how/why it works and how you can create deep backlinks, you'll be able to understand how to improve the traffic you get from Google, but ranking for more keywords. Deep link is more or less building backlinks to inner pages of your website, for example instead of just building backlinks for your index/domain, you should really build backlinks to your inner pages as well.