How do I know if my Facebook ad is working?

Judge your ads on one number: cost per result. That is the column in Ads Manager that shows what it cost to get a result for your objective, such as a lead, a sale, a trial or a purchase. The ad, ad set or campaign with the lowest cost per result wins, whatever its CPM (cost per thousand views) or click-through rate. A campaign at $10 per result beats one at $20 per result even if the second has a better click-through rate.

Wait seven days before you decide anything. The first four days are often poor or have no results because Facebook is experimenting to find who converts, and day five can be great. Do not log in all week and do not tweak: edits to ads, ad sets, campaigns and budgets can put the campaign back into the learning phase (the status changes from Active to Learning) and hurt results. Treat it as one decision a week, not as day trading.

After seven days:

1. If you are happy with the cost per result, keep it running.
2. If you are not, turn it off and go back to the drawing board with new creative.
3. If it is close, or okay but could be better, keep it running and keep adding new ads. Facebook optimizes toward the best images and text after the first week.

Every week after that, open the Ads tab to see which ads did best. Turn off the ads with a high cost per result, keep the cheapest ones, and add new ads in the same ad set to replace the ones you turned off. Repeat weekly. It is a filtering process until you are left with winning ads. In Ads Manager you can also break results down by image, headline, text or description to see which versions perform and build on those.

If an ad does not work, change the creative, mainly the image, and keep cycling through new images until something works. There are no tricks or hacks. You are feeding Facebook's AI as many options as possible so it can find the winner. Do not fight Facebook over which ads it shows. It does not reject ads it dislikes, it may charge you double or triple to show them, so replace them instead.

Look at other metrics only when you have no results, or just one. Use the link click-through rate, which counts people who clicked through to your landing page. The plain CTR also counts clicks to view comments or expand the description. A link click-through rate below 1 percent is weak and means the ad is not good enough or is not speaking to your ideal customer. 2 to 4 percent is a good zone. A high click-through rate with no results means the ad is working but something after the click is broken, such as the landing page or the form. Check that the landing page matches the ad's message, branding, colors and logo.

Also watch frequency, the number of times the average person has seen your ad. Ideally keep it at 2 or below. When it gets close to 3, Facebook is running out of people to show the ad to and you get diminishing returns, so add new ads.