This year marks the tenth Prime Day, the shopping holiday that Amazon invented for itself in 2015, in honor of the company’s 20th anniversary. The marketing effort was so successful, according to Amazon, that sales exceeded those from the previous year’s record-breaking Black Friday. Early Prime Day success was also measured in Instant Pot 7-in-1 multifunctional pressure cookers: 24,000 were purchased on the first Prime Day; on the second, 215,000.

The event has only grown since then, and not just in revenues but in meaning. Black Friday celebrates (and laments) the commercialization of holiday gifts—things people want, and that people want to give. Prime Day, as a ritual observance, has a different focus: not the desirable, but the ordinary. It celebrates the stuff you buy for boring reasons, or for no particular reason at all. This looseness is the point: Laptop computers are on sale, but also batteries; you can find a deal on ceramic cookery, or microfiber cleaning cloths. Yet what was once essentially a colossal summer tag sale, created for the sole purpose of enriching one of the world’s largest companies, has somehow managed to take on certain trappings of an actual holiday. I hate to admit it, but Prime Day has attained the status of tradition.