I LOVE FB for marketing. I started my page at about 7:00 one night and in 24 hours had nearly 300 fans. I did run an ad, which I have found to be really effective in getting fans. Now we're at almost 800 in less than a month, and I'm blown away by the following, interest and number of orders we've gotten from it. I'm not making bazillions yet, but generally get two three orders day, and the average has been about $70-$80 bucks. I've had lots of repeat business already, and the person I'm doing private labeling for came through one of my FB fans.
My website is under construction (what a PITA to get it all listed!), and so FB is the only mass marketing thing I've done. The rest has been word of mouth through friends and such, but I highly recommend FB. Run an ad if you need to. They're not terribly expensive and you can set your budget.