Facebook ads can be great, the gold rush is only starting so you can get some good value for you CPC at present..
1) Use of Image Make sure you use an eye catching image..Facebook is predominately blue so use a colour that goes against the grain and stands out and grabs those eye balls..Have it related to your product/niche to keep facebook mods on your side.
2) Name of Ad If you are going to a site outside of facebook make sure you give your ad a sharp, eye catching appealing title. If buying ads for within facebook you can't change the name of the ad and just your fanpage name appears. Use of bold and punctuation can be key here.
3) Copy/Body of Ad Facebook has lots of laws you have to abide by but ultimately you have a little bit of space to do a lot of convincing. Use as much persuasion as possible and try lots of ads. Appeal to peoples senses as it gets them on a more primeval level. Make things cohesive between the title and ad copy. Incentives and call to action are key.
4) Landing Page If going to outside of facebook have a landing page that makes sense to what the ad is stating.
5) Targeting Where you can make/break any campaign..Refine, refine, refine..the smaller the pool of potential eyeballs, paradoxically, the better. As your "pool of punters" becomes more exposed to your ad they more inclined they'll be to click it..If you have a pool of just 10k and are getting 50k impressions then on average each of those peeps is seeing your ad 5 times a day..even without a click that is good marketing on a sub conscious level (I think)...
6) Overall Mindset With ads you have to experiment, test and run with different ideas. Make sure everything is cohesive and that the ad makes sense for those you're targeting. Just recently LadyUmbrella ran a campaign for fans of fans with ad copy saying similar - great success with CPC as low as 14cent (I'm not hardcore CPC user but I think that is pretty ok, and it is a price we are happy to pay)...Get your mindset to align with those you are targeting. One ad for all of the users on facebook will not do..Have an ad for one area "People of Area X - it is time to go to the newest shop in town" or similar. Then have replicate the same add but by changing area X - if ads are more relevant to people who see them they will have much success...