To begin with, this product is, more or less, what it claims to be. The sheets come off the roll, stick to any flat surface by static, and work as a normal whiteboard should, just about.
There are however, some serious drawbacks:
1. After you've applied a sheet fresh off the roll, you can move it once, and it will loose a lot of stick. If you move it a second time the thing will start sliding around hopelessly.
(Full disclosure: I've moved several of these, and have experimented with lots of ways to try to keep them from losing their "stickiness", including rolling the sheet back onto the roll carefully. None of them work. If you find one please let me know! Also all surfaces were perfectly flat.)
2. If pen is left on for more than a couple of hours, it dries on, and you need to remove it with alcohol or nail polish remover (not even water will do the job).
(Full disclosure: this is with 3 different brands of pen (Pentel, Staedtler, and a generic) of 4 different colours, and all pens are clearly marked "dry wipe".)
3. If pen is left on for about 6 hours or more, after it has been removed there are "bumps" where the text used to be where the sheet has stopped sticking to the wall. In fact you can still read what used to be written there! This effect is not temporary and there is no way of getting rid of the bumps.
4. These bumps build up over time, and after using a sheet as a general noticeboard, to do list, etc for about a month the thing just gives up and falls off, crinkled and useless.
The box says they are "reuseable". Given drawbacks 1 and 4 I think this is a very dodgy claim indeed. Nothing's meant to last for ever but if every use visibly degrades something, and it becomes unusable after a month of light use, then it just ain't, in my opinion, a "reusable" product.
I'll end with a freindly word of warning (which is not in any way a reflection on the product). If you wipe pen off carelessly like I did, when you peel the sheet off you'll find a clean rectangle surrounded by a border of grime. Don't make the same mistake I did!
To sum up, I still would have bought this product if I'd known then what I know now, but I think buyers deserve to know the truth about a product, in advance.