Never cared for the lack of durability of it, but the colors are often bold and the surface is almost like a prime.
I have, fairly often, used it on junk stuff brought into the house and then sprayed it with just single part target semigloss waterbase clear. it holds up well for that - easier to get bold color and the look under semi gloss clear is nice, if not as rustic or "chalky".
When it's sprayed with clear like that, the durability is increased by...i don't know 50? it's better than any so called high adhesion paints that still get knocked off of corners easily.
WB clear has to be added with care, though - thin sprayed layers and each must dry to avoid hydrating several day old WB paint that will soften allowing everything (paint and all) to come off.
Added later 09 min:
We were also approached by RMP Finishes, who manufactures what they brand as Real Milk Paint made of milk protein (casein), lime, and pigment and comes a powder to be mixed with water. Maybe they'll send us a sample? Will I get high if I drink it?
if you're interested in terms of as and advertiser, they are legit. I haven't used their paint, just chalk paint bought on a whim, but same principle with the WB clear.
however, RMP offers a pretty good array of solvents and oils that are good quality, which isn't always the case for hardware store stuff. They are not cheap, but the only thing that's cheap and good is buying bulk oils, etc, from a place like jedwards, and nobody really does that other than....well, me and a few folks who can justify a minimum order amount. And jedwards is like half the cost of anywhere else, so it gets harder to hit the minimum. Who would like five gallons of oil at one time?
In solvents and oils, RMP is kind of on par with ....trying to think of something that's a reasonable comparison ... bobs red mill in grains and flours.