I believe the rule applies to any third-party payment processor that takes credit card payments and sends you the money. The most common reason for doing this is someone who has an eBay account or an Etsy store. The rule will also apply to crowdfunding campaigns, even if there is no business purpose (such as a request to help with medical bills) and this will need to be explained on the tax return.
If you don’t have an account with any third-party credit card processor, then I don’t see why you would ever receive a 1099-K.
