I can understand the market who needs housesitters, but don't understand the network benefit they'd be getting since sending out an email blast is the same - it

I can understand the market who needs housesitters, but don't understand the network benefit they'd be getting since sending out an email blast is the same - it's not a frequent enough action THEY need an app for it. As for the other side, this targets the people who are traveling, need a place to stay and happen to be going to a city where one of their friends is traveling as well? Seems like a small market. Not sure about this one...