A friend of mine is planning to start an e-commerce portal in an already flooded Indian e-commerce market.Ask him about how to get customers? The answer is e-mail marketing. It is cheap. Spamming people is definitely cheap. At the core is not a new idea. To survive with such an idea requires heavy capital investment. I am not saying the idea is bad. It is just not a new one. People have tried it before and some have mastered it. The problem is that he requires capital, which presently is not a luxury.
Fundamentally startups that require heavy levels of advertising hint to the fact that their service or product does not sell by itself. If your business plan is heavily banking on high levels of investment in advertising, maybe you need to re-look at it.