I overthrew this the first few times because it's so easy to launch the ball a long distance.  I like this for launching the ball uphill to give my dog a workout during fetch without dislocating my arm by manual throwing.  I haven't tried using this with a regular tennis ball as I don't like the dye used in those, so I don't know if they do or don't fit.  I like that I can get the ball into the launcher using the Chuckit without having to touch the slobbery mess.