This frother is a terrific buy for $6.99. It does exactly what it's meant to do.
Regarding the comments that "it doesn't froth when in liquid", the reason it might not work for these customers is that, for a frother to actually aerate the milk, you have to position it near the top of the milk - and not completely submerse it. There's no way air can be incorporated into the milk unless you do this (it doesn't work like frothers on espresso machines, which push air into the milk). So if it doesn't froth, it's the technique that's lacking, not the product.
As for the comments that the froth doesn't last long - that's true. But this is not a powerful frother, and for $6.99 all you have to do is make sure you froth the milk right before you add it to your coffee. It's a trade-off, folks, and you can't really expect a Starbuck's-grade milk frother for this low price.
I use this product with coffee I make with the Primula moka pot I purchased from Best Buy. All in all, I get a tasty cup of coffee with foam for