It may take some time, but play live dead and they will come. I think with every band I've been in, playing regularly, get into your cities free press with gig dates, Facebook, twitter, etc... We found posters at your local colleges help a lot too. I don't think there is a secret to instant popularity. I've never used online booking sites so I dunno how that works. And remember you won't get rich being a GD tribute band, it's a labor of love I guess. Good luck man!