Over at Authorize.net they are doing a contest for 6 months and a winner for every month. All they want you to do is properly display the Authorize.net badge on your Website (that you use an Authorize.net gateway with to process payments). All MSI Merchants who have a online credit card processing merchant account with the Authorize.net gateway are qualified. Check out the official announcement here. They include helpful videos to show you how to do it as well on the page. Contest runs through March 31, 2013.
Might be a good idea also to show them your site is there by sending them a Tweet after to @AuthorizeNet (https://twitter.com/AuthorizeNet) 😉