Competing with yourself

Last night while trying to sleep I was thinking about my best earning site. As I don't think there's much I can do to make it a better performer I thought why not create a second (or even third) site using the same keywords.

While I don't know if it's a good idea to start competing with yourself, it may turn out to be good plan of action for a couple reasons. Since I assume my current site will eventually get deindexed having a backup site in the same niche may keep the $$ coming in. Also since I can vary the keywords and content slightly from my current site I may start getting hits from search terms that I may be missing out on.

There may be some downsides as well, with the first one coming to mind as possible duplicate content, and of course, having several sites competing for the same keywords.

Either way I guess there's really only one way to find out. If it works out well I'll write about it again in a month or two.