It's important to remember that Facebook users are there to socialize and check up on what's going on in the world. It's a modern day personalized newspaper! Therefore it's important that your marketing strategy reflects this.
1. Since people are on Facebook to socialize these people are not in the best mindset to try and generate direct sales. Often it might be better to send your Facebook traffic to a social or news article related to your niche. This helps to spread your brand around and once they are on your site they may sign up to your email list, click affiliate links or click on your Adsense ads. But remember that not only are people more likely to go from Facebook to a short news article, they are also more likely to share that link rather than a link to your product. Market to their current mindset.
2. Another crucial part of your strategy is your use of imagery. A large amount of Facebook users are browsing from their mobiles so make sure that your photos are sized appropriately. The images you use should convey the message that you want and should also be relevant to your audience. So if you're advertising a video games console you'll probably want to use a photo of a teenager or young adult, rather than an older man. This may seem obvious but you should look deeper into your audience and use images which are more relevant to them.
3. Most Facebook users will have a couple hundred friends, like a few dozen pages and be a member of a handful of groups. So it shouldn't be a surprise that their newsfeeds are packed with a load of content from different sources. This is one of the main reasons why people say that each post you create will only reach an estimated 1% of your audience, because they have so much other content to consume. This makes it even more important to time your marketing effectively. Test out a few different posting schedules and see which perform best. Often it can be good to post first thing in the morning around 7am, just before people eat lunch and late in the evening. These are times when people are actively on Facebook and constantly refreshing for new content.
These tips should help to push you in the right direction but the most important thing you can do is to test and try and understand your audience. Every niche is different and you'll need to find out what works best in your niche.