Showing old films in cinemas tends not to work well. The hire of the reel is cheaper but an old film draws a smaller crowd. The cinema still has to allocate a normal sized screen to it (150-400 seats) which it could be filling with this weeks new releases instead. This may work however in combination with smaller capacity screens instead (20-50). The exception is when sequels are released. Showing spiderman 1&2 the day before 3 was released made some tidy profits
It's all about the smaller screen sizes with this business model. Let people choose what films they want at what time, let other people buy tickets, serve beer, etc.
Then again.. that's what you do with netflix.
I suppose the best way to differentiate from home is either far superior quality/comfort or to build a community around your cinema, like the Watershed [http://www.watershed.co.uk/].