The company provides a service that is not unique in the sense that they are just requoting what the existing laws are in the state. I am not saying that is bad, it is just something that anyone can find out.
Currently there is a service that will lower your property taxes!!! You pay them and they help you do it. They are not doing anything unique, they are simply showing people how to petition from the county assessors office.
Personally for your friend it may be a wash. If he/she does not turst his own capacity to do homework and find out what to do then yeah maybe it is best for them to call.