If you don"t use your adwords account for a while they will send you an email that says:

We're sorry to see that you've stopped advertising with Google, and we want to help you use AdWords to grow your business. We've made a lot of changes to the product to make it even easier for you to increase your sales and leads.

To help you succeed, we've created a new site packed with expert advice on how to run a successful online advertising campaign with AdWords. There, you'll learn how to:
° Get the best return possible on your investment
° Use negative keywords to prevent unwanted clicks
° Direct each ad to a specific landing page for each of your products or services
° And much more
And to help get you started with these tips, we're giving you $100 in free advertising, no strings attached, just to give AdWords another try.