Agents make the market for information less efficient rather than more.
These three barriers render the idea of agents impractical for almost all of the duties they are supposedly going to perform. You instruct your agent about your dates, preferences and price limits, and it scours the network for you, putting together the ideal package based on its interpretation of your instructions. Once it has secured this package, it makes the purchases on your behalf, and presents you with the completed travel package, dates, times and confirmation numbers in one fell swoop. A scenario like this requires a good deal of hand-waving to make it seem viable, to say nothing of worthwhile, because it assumes that the agent's time is more valuable than your time. Upon being given its charge, the agent needs to go out and query all available sources of travel information, issue the relevant query, digest the returned information and then run the necessary weighting of the results in real time.