up·side 
(ŭpsīd′)
(ŭpsīd′)n.
1. The upper side or portion.
2. An advantageous aspect: the upsides and downsides of home ownership.
3. An upward tendency, as in business profitability or in the prices of a stock.
prep.
Slang
Slang
On: "If you still didn't get it, well, sometimes you have to hit people upside the head ... to get their attention" (Howie Carr).