Periodically the space on my laptop gets lower than I like. So, yesterday I decided to get rid of the numerous apps that I have stored in my iTunes app. I was able to recover over 10 GB of much needed space.
Did you know that you do not need to keep copies of your iphone/ipad apps in iTunes, as you can re-download purchased content from the iTunes or App stores anyway.
So there are a few circumstances where you may want to keep some app's installers saved locally for yourself.