Zillow made news last week as it reported a loss of $881 million on its house-buying business last year⁠. That’s especially remarkable because house prices rose dramatically for much of the year.

Naturally, this got me thinking about fantasy football. I’ll get to that later. But first, let’s back up and talk about what the business idea⁠—often called iBuying⁠—is actually about.

Sellers want their money quickly, often because they need to put it towards the next house. But it takes a typical buyer weeks to secure financing and do other due diligence—and sometimes deals fall through.

Zillow was hoping to fill a gap between buyers and sellers. They would hunt for bargains with (what they thought to be) relatively low offers for the homes. They would make all-cash offers, hoping that certainty and speed would make up for a low offer price. Then they would turn around and sell the houses to buyers at a higher price on a more relaxed schedule.

This is not intended to be a pure “investment” strategy; it’s more of a service, where, from the seller’s perspective, you expedite the house-selling process in exchange for a fee. It just so happens that the way you expedite it is by buying and briefly holding the house yourself.

In the real estate industry, this service is called iBuying, but in more general terms it’s often called market making. It is a perfectly legitimate service performed in a variety of markets. For example, when you buy a share of stock, a market-maker firm might sell you one of theirs, and then replenish their inventory the next time a seller shows up.

“Our aim was to become a market maker, not a market risk taker,” Zillow founder Rich Barton said in a letter to shareholders, addressing the failed initiative.

But the job of a market maker is much harder in housing than in stocks. There are a couple of reasons why.

Zillow’s plight makes me think of one of my poor fantasy football teams. (Don’t worry, knowing the sport is unimportant for the analogy.) In fantasy football, you choose a roster of real-life players, and the performance of your players in real life determines your score in the fantasy league. The rosters and scores are usually tracked online. (We used Yahoo!)

The most important day in fantasy football is draft day, when you take turns claiming the players you’ll start with. Later you can add unchosen players, or trade with other participants, but the draft remains key to success.

One time, I missed draft day. This was a disaster. In my absence, Yahoo! pic