It's not the 5 posts that bothers me, it's the 4 hours. I've been on here for over a week and have only logged 2 hours 22 minutes. As a marketing professional, I believe 4 hours not only cuts out spammers, but also cuts out many legitimate prospects who get too frustrated with the limits and decide to move on.
An hour, hour and a half.. sure, but four hours? That's going to take me weeks to get!
Total time logged in: 13 hours and 6 minutes.