Yes, you need a wallet so they can send you the coins you generate.

@CaptainBeck, I never said you'd get rich, but if you are new to BTC/LTC as I was 2 months ago, it is a great way to get started with your first transactions and see how the whole thing works. In 2 months, I've made .0125 - No it did not make me rich, but got me started in the game. Took that and made a few football bets at a BTC sportsbook and now have .15 at cex.io where I am trading GHs. Not a bad way to start.