[Annalaliath]

It was the desire for power. That was the reason behind the ring wraiths and Gollum. The wraiths had a desire for power, so when the rings of power were given them they were depleted, and they succumbed tot he evil. Also with Gollum the One ring worked in a similar way, he now had the power to control his situation and his eating habits. He could now achieve his ends and not be caught for it. When Ring was his it fed the evil in Smeagol's heart till it became a second personality, hence Gollum. So yes desire is one of the ways in which the Rings of Power worked. I mean even the elves were corrupted by their desire of power, even if it were for good. Power is a very devious thing.

But that is only my openion.