This year’s Cyber Monday was a success, with total sales higher than last year’s and slightly higher than expected. Social media was abuzz with excitement for the day’s offerings, more so than Black Friday, which seems to be less popular with shoppers.

The idea that Cyber Monday is better liked than Black Friday should come as little surprise, since the narrative surrounding the latter is generally negative. People getting in literal fist-fights over toys or appliances might make some CEOs salivate, but a lot of people are sick of it, and many boycott the whole thing, staying at home or working instead of fighting tooth and nail for the best deals.

Cyber Monday, on the other hand, has traditionally been a more relaxed affair. Customers can shop from home, with a coffee or in sweatpants, and they don’t have to deal with traffic jams or worry about getting punched in the face. But an increased focus on Cyber Monday has some downsides, too. This year saw significantly higher traffic than previous years, which means slower shopping and checkouts for most people as websites strained under additional traffic.

There was also a higher than normal out-of-stock rate this year, with upwards of 13% of items being out-of-stock by the time customers were able to navigate to the items’ pages. That may not sound like a lot, but as Cyber Monday continues to set records for sales and traffic, such problems could get worse in the future.

The answer, most likely, will rely on strengthening website architecture so that customers can get the same speeds for page loads and checkouts that they’re used to, or at least not as slow as they got this year. Stock management will also be important, in order to keep in demand items in stock, as few things are as damaging to customer relationships as not being able to provide the products people want.