Facebook is one of the most cost-effective way to reach a very targeted audience. If you would like to advertise to your certain interest group (guns, privacy, drug war, etc), to libertarians in your state, or to your Alma Mater, here's how to do it.
Step 1: click on the advertising link on the bottom of the facebook page
Step 2: Click "create an ad"
Step 3: Enter the link you want to advertise (a link created specifically for your interest group is better than the main page)
Step 4: Enter the text of your ad and upload a photo (I used the FSP logo).
Step 5: Select the audience you want to target (place, age, gender, education level, key words, relationship status, sexual preference)
Step 6: Select your daily budget (best to spread your total budget out over 7 days or more). Note that the ads won't generally cost more than 40 cents per click. Paying CPM is usually cheaper than paying per click.
Step 7: track your progress and post it on the forum.
Impressions (Imp.): the # of times the ad has been shown
Average Cost Per Thousand Views (Avg. CPM): =total cost/(views/1000)
Clicks: The # of times the ad has been clicked on
Click Through Rate % (CTR): =(Clicks/impressions)*100
Average Cost Per Click (Avg. CPC): The amount it is costing you each time someone clicks (=total cost/clicks)