I've been utilizing Facebook's Promoted Posts functionality on a few of my clients' Timelines and I have to say, it has yielded some very positive results - and at an extremely reasonable cost.
The promotions run for 72 hours on any post less than three days old. So you can promote older posts as well as new posts. The cost of the promotion drops if you only promote to "People who like your page", and averages $3 - $10 per promotion. But why limit yourself!
Promoted posts allow you to reach more of the people who like your Page AND their friends - and that second part is key, because it allows you to grow your brand loyalty and following on Facebook while promoting an offer or discount to both prospective and current followers. By clicking the "People who like your page and their friends" radio button you can keep current customers warm while reaching out to prospective ones. Because, in the end you want them both to be coming through your door!
I've had good results with Facebook ads. But even while targeted, in my opinion, they spray more bullets while hitting less marks. You get a lot of "likes" but little conversion. With promoted posts, you can target friends of friends. And referrals convert into sales more effectively. I've gone almost exclusively with promoted posts to avoid spraying bullets and having to pay for nothing. It's not about the number of people who like your page. It's about reach and how many people are talking about you. 400 likes with a 90k reach and 1500 people engaged is better than 1500 likes and 20 people talking about you. Promoted posts work much more effectively toward that end.
Promoted posts have more than doubled and tripled Facebook reach and engagement on the small business Timelines I have been using them on, and have resulted in a 20-30% increase in inquiries regarding the offers being promoted. And at an average cost of a little over $10 per week!
So what are you waiting for! For $40 a month in beer money, you could be making many times more than that! Check out Facebook Promoted Posts. You have very little to lose and a whole lot to gain.