According to KFVS12 News's Does it work Wednesday (tests all kinds of as seen on tv stuff,) the bumpit doesn't work well with fine hair.
Here's a link to their website, they grade everything pretty hard and there are many products listed.
http://www.kfvs12.com/Global/category.asp?C=12373
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“All his life he tried to be a good person. Many times, however, he failed.
For after all, he was only human. He wasn't a dog.”
― Charles M. Schultz
Warning: The above post may be dripping in sarcasm and full of smartassedness.