Why did people believe Mohammed?

Seriously. Mohammed never did any miracles(as far as i know) and did not heal people like Jesus so why did people back then believe him and trust that he was a "prophet" from God? This is not a Jesus vs Mohammed thing, i just want to know why people would believe him, at least Jesus did some miracles so that makes it understandable that some people would at least take some time to listen to him. Mohammed just seems like an ordinary guy to me.....