As mentioned above one of the biggest effects for me the exposure to authors I'd never have read previously. Granted some of them I'll never read again
, but the majority of them have been quite worthwhile experiences.
The other thing I get out of it the thought that I'm making a positive difference by saving all the paper and associated carbon footprint involved in the pBooks by getting eBooks. Even if that's not true, let's not start the debate again and let me live in my happy little world.