There’s a lot not to like about Verizon’s initiative, which kicks in Friday, to charge $10 per month extra—per line!—for the privilege of streaming video at better than 720p resolution. There’s the gall that Verizon throttled its unlimited plan in the first place. There’s the pernicious creep of tacked-on charges industry-wide. But most of all, there’s this: On almost every smartphone, your eyes can’t even tell the difference. You’ll be paying $120 a year extra, with nothing to show for it.

The mini-saga began over the summer, when Verizon first announced that it would turn its “unlimited” plan into two separate plans. The first, the $75 Go Unlimited rate, caps all streaming video at 480p resolution. That’s “standard def,” a level at which you can see individual pixels when you’re streaming video. For $85, Verizon would bump you up to 720p, or 1080p on tablets, and that was it.

The official Verizon line was that most users couldn’t tell the difference. In a surprising twist, this turns out to be largely true. But that doesn’t justify breaking out its previously straightforward unlimited plan into three plans with a significant pricing gap. In fact, it makes the introduction of its so-called Premium Video tier all the more cynical.

On almost every smartphone, your eyes can’t even tell the difference.

“We're offering the Premium Video feature so that customers who buy certain phones, such as the iPhone X and Samsung Galaxy S8 and Note 8, have an option to get the highest resolution video that phone is capable of showing,” says Verizon spokesperson Kelly Crummey.

Just because a phone can show higher-resolution video, though, doesn’t mean the human eye can process it. In practice, it’s a bit like paying through the nose to access a Vegas buffet, only to find out that the prime rib has a separate cover charge. And when you pay it, you discover that your taste buds have become numbed to meat.

For help determining exactly how much you get out of that 1080p or 4K on a smartphone, we turned to Raymond Soneira, president of DisplayMate Technologies and a leading expert in the field.

Exactly what you get out of a smartphone’s resolution depends on a few factors, including the display’s pixels per inch and viewing distance. But while ppi has become a major selling point over the last several years, it’s helpful to look all the way back to the iPhone 4, which introduced the concept of a so-called Retina Display. It turns out, that wasn’t (just) marketing hype. Instead, it connotes the point at which a phone has crammed individual pixels so close together that your eyes can no longer discern them. It’s the difference between a Hopper and a Seurat.

“For a 12-inch viewing distance, if the display has more than 286 ppi, then the display will appear perfectly sharp for normal 20/20 vision,” says Soneira. “But if the display has less than 286 ppi then the pixels will be resolvable, and in principle distinctly visible.”

On a 5.5-inch display with a 16:9 aspect ratio, like you’d find the iPhone 8, 720p has 267 ppi, meaning that it falls close enough to the visual acuity of the human eye that you’re unlikely to notice a difference in practice. For a 6-inch phone with an 18:9 display, like the 6-inch Pixel 2 XL, the difference is even more negligible. On the iPhone X, even the sharpest eyes wouldn’t be able to tell 720p from 1080p from a foot away.

In fact, the only phones you can really make a case for are phablets that weigh on well over 6 inches, like the Galaxy Note 8. If you own one, and are on Verizon, and plan on streaming a lot of video over your data plan, then the Premium Video plan could possibly, maybe be worth it to you. Ditto if you plan to tether your smartphone to a larger display, like your laptop, where that resolution difference presents itself much more starkly. But even then, take care! Resolution ain’t everything.