Jeep won't start all the time???

I have a 2007 Jeep Wrangler Unlimited X. Once in awhile it just won't start. Turn the ignition all the lights on the dash come on, all the electrical works but nothing when i try and start it. No clicking nothing. It has done it twice in a week now. It will eventually start but it has left me stranded and after about 50 times of trying to start it, it will eventually fire up. Any thoughts on this problem??

 

I'd start by checking the starter and ignition.

 

You might also want to check the ASD relay. That's another common cause.