Is this a good strategy?

There are many markets out there where there are middlemen or agents. Take, for example, real estate (or, in the olden days, travel). Do you guys think it's a good strategy to leverage technology to replace the middleman (i.e. Zillow, Expedia, etc.)? Obviously the middlemen aren't going to like it one bit. In theory, it's great for consumers (more information, downward pressure on prices), but will they fully embrace the service if they still need the middleman (especially if the middleman is reluctant to use the service)? I know there are some obvious answers, but I'm curious to hear other people's opinions on this.