I invest in silver, and right now I can't pay my rent or buy groceries with it.  Does that make silver worthless?  Give Litecoin a little bit of time.  Someone will set up a bitpay for ltc (if bitpay doesn't wake up and just support it already) and hundreds of people like me will add it to their webshops.  I'm betting on btc to gain more success, and I can see a market for a secondary p2p currency.  Ltc is absolutley the most qualified for that with it's gaining momentum.