Without a product there is no business. This might sound like an obvious statement but it is soo relevant in the context of an Internet company where development work has to be undertaken in order to produce some software for people to use.
A really good product has the potential to change the nature of the Industry and without it all the the marketing and advertising in the world will not change anything.
The product is the culmination of the founders vision and the solution to whatever problem was identified, it is what the business and the company is built upon.