It seems to me that too many people mistake "revenue" with "profit" and that's where a lot of companies go wrong. When you say "revenue", you mean the monies you take in before you take out all costs. Profit, instead, is what you're left with after you covered all costs. If you can't cover all of your costs, then you have a negative cash flow, which can be very bad if you are not doing it on purpose.
For an example, look at Amazon: it ran on negative cash flow for years, but it was intended to be so to gain an insurmountable edge in the marketplace and look where they are now! However, the profit potential for Amazon was such that this strategy made a lot of sense and not all companies have this sort of potential, so this is not something that can be applied to all. Another thing that has to be considered is that growth costs not just in terms of investment but also in terms of support: the more customers you have, the more complaints you have, because, well, statistics! Managing customers is time consuming and, sometimes, resource consuming (money in various forms, computer systems, etc.) so it ends up affecting your bottom line negatively. It is a very delicate balance to strike.