I pretty much agree with the above. It depends on how clean the floor is and what I dropped. I know that a little bit of dirt actually helps your immune system, which a lot of people don't understand, so they want to make sure that everything they've touched has been 99.99% sanitized. If I drop it in the sand, though - or an overtly dirty floor - and it's something that is bound to pick up a lot of the dirt, I'll throw it out.