The SVOD Derby is about six weeks from starting in earnest, but Apple has already reconfigured the track we thought we'd use to figure out who's winning the race.

The reason? Apple is giving away a free year of its TV+ service to anyone who buys one of its Mac computers, iPads or iPhones.

There's been surprisingly little conversation about the deal, which was announced last week amid Apple's annual iPhone-apalooza, along with details on a new low-end iPad, a streaming game service, and much else.

Most of the TV+ coverage focused on the surprisingly low monthly price ($4.99) and long-in-coming launch date (Nov. 1). Both seemed intended to undercut Disney+, which will cost $2 more per month and launches 10 days after TV+.

But giving away the service is a much bigger deal than many seem to think. Here's why: In 2018, Apple sold around 280 million iPhones, iPads and Mac computers.

Their 2019-2020 successors will be eligible for a free year of TV+. I did some very back-of-the-envelope calculations that suggest the giveaway might generate considerably more than 100 million subscribers.

That presumes a set of things:

• Apple again sells something like 280 million iPhones, iPads and Macs over the next year, as it did in 2018.
• There's some overlap in the buyers of those 280 million hardware units. At minimum, some 217 million iPhones were sold last year, so figure the number of people eligible for a free account would probably be something like that number, plus a moderate additional number of people who buy something else from Apple but don't get a phone.
• A bunch of those people don't want to (or can't figure out how to) watch a new video service, no matter how easy Apple makes it, or how enticing the programming slate becomes. Amazon's experience could be a useful guide here. Only about half of Amazon Prime subscribers reportedly take advantage of the Emmy-winning shows on offer there. Figure it'll be something like that for Apple too.
• Apple, which knows something about marketing, may be able to persuade some of the people who already own 1.4 billion of its devices to pay for a monthly subscription. Even 1 percent of that group creates 14 million (paying) subscribers. TV+ also will be available on some non-Apple connected TVs, which may be generate some people who aren't already in the Apple universe.
• Apple keeps the deal going for at least the first 12 months of the service.

Again, this is all a back-of-the-envelope estimate, but within those presumptions, we can guess comfortably that Apple would generate something like 110 to 120 million subscribers, in 100 territories worldwide, who end up getting TV+ for a year. That's a whopping big number compared to everyone else in the SVOD Derby.

Netflix, which has been at it for two decades, has around 152 million subscribers in 192 countries. Every one of the other major competitors is far behind, or is only available in a few countries, or hasn't even started yet.

So what does this mean for those of us charged with toting up winners and losers?

First of all, how do we value Apple's tens of millions of free subs, however many there may be 12 months from now? My esteemed colleague Alan Wolk suggests that free subs are typically discounted in enterprise value, in part because those customers in turn tend to put less value on what they've been given.

But what does it mean if Apple has 100 million or 110 million or 120 million subscribers? How do we compare the mostly free subs of Apple, at whatever level of engagement, to the paying subs that Disney+, HBO Max, CBS All Access, or Peacock or Vudu have by then?

I can't help thinking of Spotify, which had 108 million paying users worldwide by the end of Q2 this year, and another 124 million users who use the ad-supported version at least occasionally. It's the world's biggest streaming-music service.

Its biggest competitor is Apple, which likes to emphasize that Apple Music has only paying subscribers, and importantly, has more paying customers in the United States than Spotify. It's been a news-release bullet point for the past couple of years, but not a very compelling one.

Apple no doubt will be making a different argument when it comes to TV+. The question to me is how everyone else values it. For Apple and many of its future competitors here, what counts as a win will differ compared to everyone else.

The bottom line for Apple is whether getting people into its video service, and keeping them there, can drive revenue or loyalty, and make up for the flattening sales of those iPhones. This will be especially important in what's considered to be a less innovative year for the newest models.

For Disney+, the measure of success will be how well it feeds the needs of fans of Marvel, Pixar, Star Wars and other brands, and sends them back into its broader brand "washing machine" resorts, rides, merchandise, games and so much else.

Maybe the newly named Peacock service from Comcast will rely on giveaways to boost its numbers too. After all, between Comcast and Sky, it can reach around 50 million pay-TV customers and perhaps even more Internet customers

But for everyone else, if Apple actually achieves these gargantuan numbers, it will create challenges for all the other newcomers, and possibly complicate the narratives of the existing services.

Netflix will continue to be measured by its subscriber count. When its numbers underperformed last quarter, its share prices were punished, especially for that slight drop in U.S. subs. It seems likely to continue to live and die on that metric, but Apple's likely imminent girth will complicate that corporate narrative.

And so it will be for the other up-and-comers hoping to challenge Netflix for the throne.

But we'll need to figure out how we're going to value a service that has 5 million, or 8 million, or 10 million subscribers after a year of operation in the wake of what likely will be gargantuan numbers for Apple. Is their number still a win? How does it further the company's larger corporate aims?

It'll be the biggest question we'll need to figure out as this derby gets started in earnest.