Was the NFL's first streaming playoff game a success? We still don't know.

• Saturday's Chiefs-Dolphins playoff game was primarily streamed on NBC's Peacock — an NFL first.
• NBC says it was a success, citing viewership and internet usage numbers.

Most people who wanted to watch the Dolphins-Chiefs playoff game this past weekend had to do so by paying for Peacock, NBCUniversal's streaming service. That was a first for the NFL, which has always put its biggest games on conventional TV.

Did it work?

That depends. But a reasonable answer is: We don't know.

On Sunday, NBC said the streaming game was a success: Depending on how they measured it, the network said the game averaged an audience of 23 million to 26 million viewers.

While that's almost certainly lower than the audience the game would have gotten if it were on regular TV — last year, the viewing audience for this round of the playoffs averaged around 28 million, and none of those games had shots of Taylor Swift cheering on Travis Kelce — NBC took a victory lap anyway and said the game broke records for most-streamed event in the US.

It is noteworthy that the event seemed to work from a technical sense: For years, people have been wondering how the US internet infrastructure would hold up if tens of millions of people tried watching the same thing at the same time. Looks like that's no longer a debate.

But we won't really know if the game was a success for NBC until it announces the most important metric: How many people paid for Peacock so they could watch the game?

Because that's the real reason NBC paid a reported $110 million to host the streaming-only service: It wanted to boost Peacock, which has until now trailed the other big streaming services.

And that bet makes some sense. Other streamers have poured billions into making and licensing TV shows and movies to lure viewers, but the NFL is the most popular thing on TV, period. Why not see if a big game moves the needle?

Before Saturday's game, NBCUniversal's parent company, Comcast, had said Peacock had 30 million paid subscribers. That's a combination of people who paid directly for the service and some of whom got it as some sort of package deal from Comcast, the country's biggest cable company.

It's reasonable to assume that a significant chunk of NBC's audience total came from that pool of viewers. And a meaningful number of viewers came from audiences in the Miami and Kansas City areas, who could watch the game on regular TV.

So how many other people paid up — the lowest price available was $6 for a monthly subscription, but Peacock was offering a one-year package for $30 — specifically to watch the game?

NBC hasn't said so far. We could get subscriber numbers if Comcast decides to break them out in the company's earnings call next week. In the end, that number will be crucial for the network. As will the number of subscribers who stick around to watch other programming on Peacock, like this summer's Paris Olympics.

That's because churn rates — viewers signing up for services then canceling for various reasons — have become a major issue for streamers.

But that number will almost certainly determine whether NBC or any other service pays up for a streaming-only playoff game next year. And/or how much they — and ultimately you, the NFL viewer — will pay for it.