This assumes that the other competitors aren't vastly overcharging for their services. The current commission structure for most brokerages is still based on a time when computers couldn't execute a trade nearly instantly and a lot of paper and people were involved with the execution. There's really no good reason for a trade costing between $5-10 dollars to execute today. So far my experience with the Robinhood app has been pretty great. When you aren't trading thousands of dollars per trade, not having a commission is pretty dang nice and removes a good sized barrier for light hobbyist investors like myself.