engine - 6:02 pm on Aug 1, 2012 (gmt 0)
Profit is the key to a successful business. If you don't make adequate profit you can't pay your investors (which may be just one individual), and you can't re-invest. If your margin become too thin, as soon as the business hits tough times there's nothing to fall back onto.
Running a few product as a loss leader is entirely different and may give the company the opportunity to up-sell, or to add normally-priced products to the cart.