I had a free listing in BB for awhile, started to do a paid one. But it finally dawned on me I was already getting no work from it, just ITB's. I spent lots of time sorting out the e mails, getting prints, doing quotes, etc. But 1 GC told me I'd get very few jobs, as I had to ask for deposits & few GC's will pay them. I'm a very little guy with little cash flow. So I cancelled out with it.
If you have cash reserves, you may be able to get some work with this. See if they will give you a trial free listing.