Yes, they do. They even have all the Hookups ;)
If it is a simple trip with just a couple, not really. However if you have 10 family members coming from different parts of the country to a single destination and going on vacation they can be a big help. Most don't charge anything for their service as they make money from the places they put you up. If your travel agent is a good one they will listen to your needs and match you with the appropriate accommodations for your budget and needs.