I have read in many articles where it is claimed that the 737 is the best selling a/c of all time.What came to me is why was the 737 a better choice than the 727. The 727 seemed just as reliable and appeared to even have more space and power than the 737.(I am talking about before the 737-800 and so on). Did it have any thing to do with it's turn around time on flights? Could anyone with an idea share it with me. I'd be greatful.