How long to try Facebook ads that have no sales before canceling them?

I would recommend to stop when you spend more than the sale price of your products.

Hey Nora, Anne here from KeepShoppers. Usually when Facebook ads do not convert for a few days, and you were expecting it to generate sales, you're missing something in the ad settings. (campaign flow, good targeting, poor pixel feedback, or others). If your campaign had been running for a week and you haven't received the results you were aiming for, I would suggest that you recheck your adds and see what might be the reason. Did you target the right crowed? Do you get more traffic but no sales? This may indicate you are targeting the wrong audience. Are you aiming for cold audience? if so this might be why you do not have any sales. If this is the case your goal isn's sales but brand awareness therefore, this isn't a bad result. Consider trying to retarget your ads to market to the people who have already visited your website - return customers can bring pretty easy sales and tell their friends about it. Also for some products FB isn't the right tool. You could try Pinterest (if that fits your brand), Instagram or try joining some free groups where you can promote your product. Good luck!