THIS PROVEN technique seems lost on many digital marketers.  Just because there are 900 million people on Facebook, doesn’t mean you need to appeal to all of them.  
Start a Facebook marketing campaign and condense your search from 900 million to the target audience that you’re trying to market and sell your product to.  This allows you to pinpoint demographic info, location, keywords, etc. for your campaign.  When you fill out this information, Facebook calculates the potential number of users that fit your target Facebook profiles.  For example, a single, 25-45 year-old person who lives in the United States and has the same particular set of interests as your company; try to think outside-the-box when doing this, e.g., book authors, celebrities, magazines, or any other interests that your target audience might like or have in common with your company.  
The more interest you can narrow your search down to will increase your click and “Like” rate.  Remember, you’re paying for each of your clicks, spending between $0.39 to $0.75 per click, so you want to make sure you are targeting the exact audience that will view and continue to view your website. After you enter all of the desired information, Facebook then will narrow your search down to X amount of users.  Change any variable and the user number is automatically re-calculated.  Your ad will then only go to this group(s) of users, otherwise known as your target market.  
The next step is to set your daily budget – how much you’re willing to pay-per-click.  Higher bids will give you a better exposure rate.  I suggest trying a small experiment to see how this works. Market tests like this will help you keep your budget streamlined as things don’t always perform how we think they will. In case your plan doesn’t work out the way you think it will, if you’ve used a small market test, you can evaluate the sample’s performance and make adjustments as-needed.  
Here’s another trick for highlighting your target market: If you look to the top of your Facebook page, you’ll see a search bar.  If, for example, you’re a realtor in the Orlando, Florida area, use words like “Orlando, FL Realtor” (make sure you put whatever you’re looking for in parentheses), or the location and state that you’re trying to connect with.  You can then see all of the people that have used those words or the use of those words in a sentence; e.g., “I’m looking for a place in Orlando, Florida.  Does anyone know a good realtor?”  You can then send them a friendly message making them aware that you can assist them in this very task.  Simply send them a brief/non-threatening message saying that you’re an Orlando-based realtor, and you would be glad to show them around and you have a couple of properties that would be perfect for them.