Check your E-mails, I got one from Amazon with an offer for 200 free coins with the purchase of
The Last Town* by Blake Crouch. (Book three in the Wayward Pines Trilogy.)
Dear Manabi, when you buy the Kindle book The Last Town, you earn 200 Free Amazon Coins. Use your free Coins to buy top-rated Apps and Games in the Amazon Appstore.
It's not a global offer however, behold the fine print:
Offer valid only for the recipient of this email. Offer expires on 8/22/2014. You will receive your free Amazon Coins within 48 hours of making your purchase. Your free coins expire one year from the date awarded and are subject to the Amazon Coins Terms & Conditions.
Personally I think it's a lousy deal, but it may be useful for others and I'm sure some people who got the E-mail had it end up in their spam folders by mistake.
* This is a clean link, I didn't use the one from the E-mail.