Why do you need to enter your billing address on amazon.com?

Please help me --- Read this mail and ans me ( What is this mail )?

• Google Webmaster Tools: Get $100 of free Google AdWords advertising for your site Dear Webmaster, Thank you for using Webmaster Tools! We hope you are enjoying our latest releases, which include richer search query data, improved malware notification, and an SEO Starter Guide. While these tools are a great way to optimize visibility, many webmasters also use Google AdWords to drive traffic to their site. We want to give you the chance to experience the effective and measurable results that Google AdWords offers with a free $100 in advertising. Try it today! To get started with AdWords, please follow these 3 steps: 1. Visit www.adwords.google.com and click "start now" to create your account. 2. Follow the instructions to choose your keywords and create your ads. 3. Enter your billing information and input your unique coupon code exactly as shown below.​​ Your personal coupon code: FQ5T-5QZE-JV74-VEPD-QRG Key Benefits of Google AdWords Maximize the effectiveness of your search ads. You can more precisely analyze the performance of your search ads, giving you insights on how to increase conversions. Target the whole world, or just your neighborhood. Google AdWords makes it easy to advertise to your town, country, region, or to everyone. Pay only when people land on your site. Google AdWords is performance-based. You only pay when someone clicks on your ad and connects to your website. *Terms and Conditions Promotional credit must be applied to a new AdWords account within 15 days of creating the AdWords account and is valid only for new Google AdWords customers with self-managed signup accounts. Advertisers will be charged for all advertising that exceeds the promotional credit. Advertisers will need to suspend their ads at the time the promotional credit amount is exhausted if they do not wish to receive additional advertising charges. Offer subject to ad approval, valid registration, and acceptance of the Google AdWords Program standard terms and conditions. The promotional credit is non-transferable and may not be sold or bartered. Offer may be revoked at any time for any reason by Google Inc. One promotional credit per customer. Advertisers with self-managed signup accounts are subject to a $5 (CAD10) activation fee and Advertisers who choose prepay billing are subject to a $10 (CAD20) minimum prepayment fee before their account is activated. Any such prepay amount will be credited to Advertiser's account once account is activated. However, these fees will be debited from the promotional credit if Advertiser's account was created after July 15, 2010, that is, you will not be charged the activation fee. Offer valid only for sign ups through the URL provided for the promotion by customers with a billing address in the US or Canada. Your use of this voucher and/or the promotional credit constitutes your acceptance of these terms and conditions. Offer void where prohibited by law. © 2011 Google Inc. All rights reserved. Google and the Google logo are registered trademarks of Google Inc., 1600 Amphitheatre Parkway, Mountain View, CA 94043.

• Answer:

  Get started with AdWords and get ready to spend loads of money - AdWords is Google's money making machine - use with care or get bankrupt. Perhaps explore Google Express or cheaper options (see the source link for tips and PPC experts to follow)