I trade one of my planets for all sorts of goodies. I can get technologies, weekly sums of money, trades goods, whatever. It's the same planet over and over. I can get something like 900 credits weekly for this planet. They take ownership, but lose it due to my overwhelming influence. Perhaps the perceived value of a planet should be decreased in proportion with the influence of the originating side subtracted by the influence exerted by the planet itself. It seems a bit odd that the AI doesn't learn that this is a really bad deal. In the meantime, I get to poke fun at the AI for believing in something that's too good to be true.