I bought it last year, my son was not interested in any other educational DVD's except this and his other favourite is baby signing time. I am not sure he has learn lots of words, but some of the things he can do. Anyway, more stimulation helps his development so it's fine for me.
Baby Signing Time, teaches sign language, and in scientific articles I just read that helps children not only to comunicate early with signs and helps children speak earlier but also increase their skills in reading too. The person who created signing time (there is a whole series for toddlers or older children, well adults can use that as well, and there are two for babies-baby signing time) has a daughter who's deaf but she has master her talking and reading skills a lot sooner than children who's deaf, I can't remember if she has just develop like normal children or even better. I love that video as well. You can buy it from geobaby's hkshop.
Check www.signingtime.com