From what I gather 7500 is still enough to make a positive difference. I read an article a while ago that the idea of 10,000 steps came from a Japanese word that was intended more as an approximation than a specific goal.
I like to get 10,000 steps, not least because my regular route for gives me about 9000-9500 so it's a small hop to get over that handy number. If I'm running it takes more - my stride length increases so I end up with more like 8000 steps. 2000 steps doesn't sound like a lot but if I'm at home for the rest of the day it's surprising how few steps I can end up taking, especially when my tracker doesn't always count them if I only take a few at a time. The other night I got up in the night to go to the bathroom and apparently I managed to get out of bed, walk to the bathroom, walk back and get back into bed, while accumulating 0 steps. Indoors I'm very light on my feet.