So you're asking if it's worth setting up a business facebook page?
At the moment, I've got 204 'Likes' on mine. I booked £150 of work through it this week, £70 the week before, and got another £70 job booked in for the week after next (this doesn't include referals, just the jobs booked directly through Facebook). This is more than I've had off my own website - which is subject to being kicked in the ar*e whenever Google feel like it.
So for me, yes it's worth it. There's a lot of people on there who will make an enquiry just because there's an ad break in Jeremy Kyle, but you've got to accept that as part of being easily contactable, people will ask just for the sake of it.