BZ works for me, last year they gave me over 400k in business, forget about the mac work and referrals, been a vendor for 5 years, there service is priceless.
Took me 12 months to figure out how to make this work, in the beginning, I was ready to throw throw the towel in.
What I found was people that inquire (for the most part) will be buying, some right away, some a year from now, or some never. It does work and it is way cheap!!!!!!!!!
You need to handle these leads a specific way, much different than most our accustomed to.
I bet most that can't make this work are also those that are in denial about IP systems
Also there is a knack to get credits for the BS leads (competitors)
Don't ask me how I have made this successful, I will not share that for obvious reasons.