I self-published through Smashwords and Amazon last Wednesday. I made sure everything was perfect and had 6 beta readers over the course of 8 months before putting it out.
It's been over a week and I admit to doing hardly any promo (other than that little linky on my siggy).
I've only had 6 sales, one of them was a freebie to a friend, and I've only made $9.
So, experience does vary a lot