no need to get plenty of backlinks, just try to get high pagerank backlinks, PR5 and above and the next update you'll atleast have PR3
Always post unique & good content so that visitors can visit many times your site to read the daily updated content. You will get good PR.
I agree that traffic character will not affect pr. Dofollow inbound links from high pr sites is one of the most important factors to increase the pr. I just doubt, which one more effective, backlinks from blogroll pr blogpost?