After your ad has been running for a few hours, you'll begin to see some meaningful stats in your ad manager. You can choose to view sets by campaign by ad set, or by individual ad. If you're just getting started with advertising, you'll most likely be running only a single ad. So it makes sense to view those stats. You'll see plenty of numbers here, but what you really want to pay attention to is your your CTR, which is your click through rate to your link. You see plenty of numbers here.
But what you really want to pay attention to is first your Ctr. This is the click through rate to your like, Facebook counts and tracks all clicks on your ad, whether it is to like your page or check out your offer. But the one that really counts is the Ctr to your landing page. The higher the percentage, the better. The other thing you want to pay attention to is your CPC, which is the cost per click to your link. This is how much you are charged every time someone clicks through you through to your landing page.
The lower the costs, the more effective your ad is. If you find your CTR is low, then it's time to take a look at your mass message to your market. Is your target audience interested in what you're offering? Is your ad copy failing to clearly show the benefits of your offer? You should aim for a CTR of 2% or greater your CPC is closely related. And high number likely means you have a message to market mismatch.
Ideally, you want to tweak your ads to improve the stats. But a bit of caution here, don't change out the entire ad at one time. Doing so will leave you no way of knowing what was working and what wasn't. a far better choice is to change one thing at a time. For example, create an ad with a new image and test that against your original. If it performs better, then try changing the headline and test Again, a systematic approach will allow you to see exactly what works with your audience and what doesn't.
And remember, you can create multiple ads with a single campaign and run them simultaneously. So you can see which one's perform better. Then turn off the ones that aren't working.