I thought I would give a example of what can happen when you run a campaign on facebook.
To explain the following snapshot a little to those who have done no advertising on facebook, this is a campaign that I can run on facebook to advertise Money On Computer Forums. The following snapshot shows the statistics on what happened in approx. 60 minutes after activating the campaign to run.

- facebookads.jpg - Viewed 19117 times - (151.4 KiB) - 556 x 386 pixels
The maximum cost per click I set was 0.25 cents. I set the daily spending cap to $5.00 dollars and set a maximum cap of $50.00 for the entire campaign. So far, I have received 82 hits directly from the ad to my website homepage after it was displayed 99,615 times within approx. 60 minutes total running time over a two day period. This is also reflected in the increased number of people online within an hour on the MOC web site, which is displayed at the bottom of the MOC homepage, and which has now reached 59.
Facebook emailed me a redeem code for $50.00 advertising, and I thought I would use that to show an example of how to use it to bring free traffic to your web site. If you received a redeem voucher from facebook in your email, make sure you use it!
I don't recommend this as a normal way to advertise, targeting 194,885,320 users lol as obviously you will reach your spending limits pretty quickly, and you may well want to keep a steady flow of traffic coming in over a longer period of time to more suitably targeted traffic. Whatever works for you and suits your objectives is what you need to work out, I just wanted to show a cool little example of the mega traffic reach of facebook advertising.
At this point with 82 hits to my site, I paid 0.11 cents per click, well lower than the 0.25 cent maximum I set per click, and which once again is well lower than facebooks suggested maximum bid limits per click as you can see displayed in the snapshot above. New members also joined MOC Forums so I'm obviously pretty happy for those new members to join here.