Life changing

Or product information of groceries printed on the packaging, which makes it easier to check for nutrition & allergies. It could even have your phone suggest recipes with what you have in your fridge. Next, this might even help supermarkets in their objective of providing a seamless experience for customers who can pay without taking their groceries out of their bags. (Like Amazon Go, but based on Spray-on tech instead of Smartlight & cameras.)

Spray-on memory vs. Smartdust

The most important difference is that Spray-on memory still needs some kind of printer to print it on a surface. Smartdust does not need that. It is like dust. (What’s in the name. 😉 )
Next, Spray-on memory can only contain a small amount of memory. Which is a good start of course, but Smartdust is (can be) connected, so can have an indefinite amount of memory.
This last thing makes Smartdust maybe a bit creepier. But it makes it also more fragile. Fragile to hacking, connectivity loss, et cetera. Spray-on memory is an offline storage, so it has none of the disadvantages that come with being connected.

Nissan Leaf

Spray-on memory is like the first commercially available Electric Vehicle

Spray-on memory is awesome! Like the first commercially  available Electric Vehicle (EV).
But that car had a small reach compared to EVs nowadays, like Spray-on memory has only a small amount of memory. Smartdust will blow these disadvantages away. And with the current speed of Nano Technology R&D, this might just be available sooner than many people think.
But please be aware that something like product info doesn’t need much memory, so it is very applicable to this Spray-on technology. Looking forward to going shopping and walking out the door without paying at a cashier or self-scan-portal.