I am wondering whether this is a site glitch, or a major move to compete with Craigslist, but rental posting on Backpage appears to be free at the moment...
Rental posts typically cost a dollar on Backpage, either in apts by owner (no brokers), apts broker fee, or apts broker no fee. Yet today, everything in the rental section seems free.
This is a completely different model than Craigslist, that allows owners to post for free, and charges brokers $7-10 per post to brokers... (and enforces everything rather loosely and randomly)