If you have time to spend, yes join facebook.
If you can monetize the traffic, please join.
Otherwise, stay away. Too much timeconsuming for your own good 
*I´m ironic*
EDIT:
100% on the nail:
@casinobonusguy 150315 wrote:
I have facebook but same with the myspace fad it dont seem to produce $$$.I rather spend my time on my sites to get search engine results.I really cant see a person wanting to gamble pulling up facebook to find us.