There are many kinds of fraud with different patterns. Some have a lot to do with what you sell, but others can affect anyone that takes credit cards. For inst

There are many kinds of fraud with different patterns. Some have a lot to do with what you sell, but others can affect anyone that takes credit cards. For instance, fraudsters that have received a bunch of stolen credit card numbers will want to test which cards are still good. They'll do that by making a small purchase at an online retailer, and if the charge clears, then use the card to get something illegitimately. While you might not be a good target for that second step, anyone that takes credit cards and has weak fraud protection steps will be a target. What one day looks like an unexpected spike in sales becomes a huge spike in chargebacks later, as all of those sales were fraudulent. I am pretty sure there's been stories in Hacker News about this.