Sure, it's not original or unique, but that wasn't your question. Facebook itself wasn't particularly unique when it launched.
1. The product isn't useful
2. The product is useful but nobody is using it.
3. Ok, a lot of people are using it but nobody is buying it.
4. Ok, some people are buying it but the product is not innovative. Somebody invented it first. <--- the person is here.
5. Ok, the product is innovative but it's not like it will cure cancer!!!