I have lots of Frequent Flyer Points, most of them via travel. But I know many people that only travel via plane a few times a year and have just as many as me. Those miles can be built up quickly, but can't be spent as quickly.
I have used miles for several domestic and international trips. It has worked very well for me because I don't mind an extra connection, long layovers, or strange travel times. The point is, you must be flexible.
You can also lose miles or points if you don't add or use them from your account. Every year it has been more easy to lose those miles or points. Airlines have been adding many tools and telling travelers about techniques in using miles.
Using and Losing Frequent Flyer Points