I had opened a blogspot account many years back, and it was linked to by about 4 blogs then. Few weeks back, I checked and saw that the blog had a PR of 4. Does the age of an url have anything to do with PR? Or is it because the blog was about a topic very very few people talk about. But there aren't even many contents, only about 20 posts. I had linked to each post though, from another of my blogs.
Age helps, but in general, PR will be created by quality incoming links, and you won't need much to get to a PR4, just a few very good ones. I'd say it's a keeper, nice things to be done with domains like that
it could have been sandboxed initially. I did link trading on one of my sites and 6mo after launch it is a PR4. I never saw it being a PR1-PR3...
Might take a while to pick up any PR at all, i have noticed so on my sites as well. Just means you have to be a bit patient