I rarely use file sharing services like Rapidshare, since they just keep your files for a while.
But maybe you like Rapidshare, just as what Orli Yakuel from TechCruch said:
So why would you use an file-sharing app anyway? Actually for many reasons: for larger files, for privacy, multiple files, file format support, and more.
If you have some of the reasons Orli mentioned, you can check out the 16 file sharing apps shared and compared by Orli.
For me, although they are free, if I can upload a file to Rapidshare or other file sharing services, I can share the file with all the world, so instead I will upload the file to email, youtube, twitpic, or other social media.