It's very important that you follow each of these steps if you want this to work. If you follow the steps, it will work perfectly. However, there are reviews online from people saying it didn't work for them. I did a lot of research, and this is how to make sure it works for you:

-Do NOT use low odor markers
-Make sure the paint isn't expired. (See how to do that here: http://www.amazon.com/gp/review/R2D94...)
-Sand the walls so they are completely smooth
-Wait 30 minutes between coats, put on 5-6 coats
-Wait 3 days before putting any markings on the wall