It allows easy screwing around with nontrivial system configurations without worrying about interfering with other important configurations. Say, if you want to

It allows easy screwing around with nontrivial system configurations without worrying about interfering with other important configurations. Say, if you want to mess about with an assortment of Linux installations, $25 gives you a platform cheap enough to have several handy to tinker with and still leave primary computer(s) in their workable state; >$250 may give you pause because you may not have very many units subjectable to misconfiguration, crashing, system wipe & reinstall, etc. I'd like to tinker with various OSes, but at present all my computers are either expensive enough they must be devoted to useful reliable purposes, or are cheap enough they're grossly underpowered to do anything interesting. The RPi is cheap enough - and easy enough to slap on any available I/O - to do frequent ground-up tinkering with.