Is it feasible to acquire a Pro account for free?

Yes, there is.

1. To have a Pro account for free, you must be in the Top 3 (most visited profile) in a roll for three weeks. All Pro account users will receive a reward for ranking continually in the Top 3 for three weeks. However, if you are a basic user (Free Account), you will not receive the published benefits but will instead be given a free one-month upgrade to a Pro account to compete for the following ranking period.