Probably much to the disgust of most people on this site, it depends what you use it for.
If you think you will make money from it, forget it and depending what your marketing ideas are it can work well for a few.
It is all down to careful thinking, to reach 180k people in one hit is a good thing to get your name out there, and quite a few hundred will just look at your website link and to offer a slightly better deal on your website than what the offer is people will book it. Use little product, an hour of someones time on minimum wage is minimal...but again time is money. To leaflet to 180k people would cost an awful lot more and you still have no guarantees that you will gain clients.
Again I see peoples noses turning up at this post..but I'm not ashamed to say I have done it - I got 15 people (yes hardly any- that was the idea and it worked) through a deal for a cut and blow dry, slotted them in when I wanted to, on days where it was a little quiet over the course of twelve weeks, but I got far more clients from my website. We sold retail and retained a few of the 15 clients- some you win some you lose. We had a good response to people booking online just by being curious after seeing the name.
I understand the principles about not devaluing your services but again this is individual to circumstances and what you are trying to achieve, to use it in this way can be effective, it's the same companies that you see on there continually that interests me as they only hope to retain clients which isn't always successful or the clients that some people wish to have.
I hope that gave a different outlook on this for you.
As for skinbase, I think maybe the beauty rooms post below may be a point to consider.
