It's good news to see people wanting to do the same thing, as it's a kind of validation.

I can understand your being upset by the wholesale copying.

Sometimes the competitor can't actually deliver on what they promise: if you contact them, you could offer them affiliate marketing fees for sending traffic to your site (which presumably can deliver on what it promises).

You can probably report the ODesk job offer to ODesk. Their policies / Terms of Service probably include something like "Don't post jobs which constitute intellectual property infringement."

Lastly, you could just be the best in your category, and beat your competitors regardless of their shady tactics.