I mean, just looking at this from a practical stand point, how many people actually look at 600 posts a day, that seems really excessive. I doubt 95% of twitter users are going to hit that limit. Though it would look a lot less like a money grab and more to keep information gathering if he'd made it a flat 6000 across all accounts instead of just the verified ones

Lolz, well in that case their screwed I assumed it was based of interaction. Thats the exact way I used twitter when I was on it. Scroll for a full min until you see something intresting.