As a web publisher and affiliate marketer, I've had domains DDoSed at least 4 times in FY10. The worst of it being twice in two days on two separate domains both targeting the same campaign by the same botnet based in Turkey.

Each one cost me money, but the two in two days cost me thousands. I was hosting a VPS on Rackspace and did everything I could to mitigate it but ultimately the attack stopped because they wanted those resources directed elsewhere.

After the first one, I hooked up with a smart guy on Twitter (http://twitter.com/sempersecurus) that tracks botnets. He allowed me to sinkhole the domain so that he could collect and aggregate the data.

To stay defensive, I put some .htaccess blocks in for countries that are clearly well outside normal buyer patterns. In each case, I know a user (read: a human) saw the campaign and then put the DDoS in place so I hoped, by the .htaccess blocks, to prevent them from seeing the site altogether. But I know I really need to be a much more knowledgable coder to be proficient at deflecting these in the future.