I was searching on Google for all things Google, as you do, and found this great site called Hidden Audience. Check out this new Cheat Sheet from Hidden Audience around Retargeting. It’s great information and will open your mind to other ways of bringing current and potential customers back to your website.
You’ll be amazed at what Retargeting can do for your conversions; it makes your users feel like you’re stalking them, but if done tastefully it can actually bring them back to convert when they have abandoned a cart or to remind them of special deals after they’ve converted on a purchase; it’s like a salesman working for you 24 hours a day.