YouTube TV, the skinny bundle launched earlier this year by YouTube, will be the presenting sponsor of the 2017 World Series on Fox. Take a moment to digest that: the iconic World Series won’t be presented by a beer or soda company, an automobile or truck manufacturer or a wireless carrier. Instead it will be a skinny bundle!

The sponsorship includes national TV spots, on-air call outs during each game, branding on MLB’s digital properties and social media accounts, plus in-stadium promotion and MLB players competing in postseason promotional events. YouTube creators will also produce behind-the-scenes content. And select fans will get VIP access at the games themselves. The value of the deal wasn’t disclosed, but surely runs to 7 or 8-figures.

The decision by YouTube TV to step up for the high-profile sponsorship marks a significant milestone in the development of the skinny bundle industry. There are at least 5 other major providers: Sling TV, Hulu, DirecTV Now, PlayStation Vue and Comcast Xfinity Instant TV, with more coming soon. The central premise of all skinny bundles is to offer fewer channels than pay-TV’s traditional multichannel bundle at a lower price point. Skinny bundles are emulating SVOD services by also emphasizing greater accessibility and less commitment.

Despite the number of entrants, consumer awareness of skinny bundles is still quite low. While a precise count of total skinny bundle subscribers is hard to pinpoint, it’s surely well below 5 million. All of that means that YouTube TV’s World Series promotion will be the first time millions of Americans will be exposed to the skinny bundle concept generally and the idea that the YouTube brand is being extended to a value proposition far beyond short ad-supported, on-demand clips for which the site is universally known.

Among the many issues I’ve highlighted in the past with skinny bundles is the “Swiss cheese” problem of certain key networks being missing. While the main broadcast TV networks - which still have the biggest audiences - have become more prevalent in skinny bundles, they’re far from ubiquitous. In fact, according to the CNET tracker, Fox itself is still only available on YouTube TV in 25 of the top 50 markets in the U.S. and among the next 150 only in Memphis. (YouTube TV also says that in 7 of the total 26 markets, there’s only VOD access for Fox, so presumably no live baseball.)

That means lots of people who are exposed to the YouTube TV brand during the games and are intrigued enough to follow up will soon discover the limitation that Fox and other broadcast and cable TV networks are not available in their area, which in turn diminishes the value proposition (and of course the ultimate impact of the YouTube TV World Series sponsorship).

Obviously by going forward YouTube TV feels it’s worth the risk. But the Swiss cheese problem for skinny bundles isn’t going away; by definition offering a lower rate means some networks won’t be carried. This creates real challenges for doing nationwide, scaled advertising as SVOD competitors like Netflix and Hulu have done successfully.

How all of this ultimately works out for YouTube TV is still a big question.