ELF website and it rivals the cult favourite Urban Decay Primer Potion. Mine fell apart after a few uses, the cap unglued from the lid, it sucks, but it doesn't change the performance of the product at all. This product serves the same purpose as the UDPP, you put in on your eyelids and it acts as a base for your eyeshadow, keeping it in place and from creasing all day. You get about half as much product in the ELF primer than you do in the UDPP, but more than half the price (for the same size equivalent). The texture is a bit different, but I think the product is very comparable.
Rimmel's Smokey Brun quad here for the look, I wanted to use some cheap eyeshadow to really show any variation. I find with MAC shadows they always look good, regardless of what primer you use.
So for the purpose of "does it perform the same way?", I think the ELF Primer does a fine job. I think for $3 it's a really good buy if you are on a budget. If you used high quality eyeshadow you would not notice the difference between this and UDPP. Urban Decay has started to package their primer in better packaging recently, I am not sure if this is permanent though, many people dislike the UDPP packaging, as do I and should really be buying Too Faced shadow insurance instead, the ELF primer falls into the same problem, the package isn't great, but the product is totally fine.
Have you tried the ELF Mineral Eyeshadow Primer? How did you find it?