High PR results from a lot of incoming links to your site and it does indeed bring traffic, however if you site sucks most of those people that visits will leave.
So you're always struggling to maintain anyone. On the other hand, a site that's new with quality links and advertisements can get more traffics although their links are not as much as the one with high PR.
The key here is where is your link coming from!!
If it comes from a site with 1 million visitors or such, well you've just hit a home run my friend.
