Do you think Dell will be successful in its “invasion” of the printer and ink refill market? What circumstances might affect its successful entry?

A cash cow is a product or division that is well entrenched with good profits in a low-growth market. Potential competitors seldom are attracted to such a market or willing to make the investment needed to go against a dominant firm. With no competitive threat, this firm has little incentive to invest more and is content to “milk” the profits of the cash cow, especially if the cow is as essential as ink is to a printer.
However, danger can lurk in this complacent mindset. If the product is profitable enough, and if entry into the industry is not prohibitive, then interlopers may still be attracted, or in Dell’s case, with H-P’s cash cow subsidizing the money-losing PC sector in direct competition with Dell, it seemed worthy of attacking.
Therein lies the danger of being greedy with cash cow profitability. Any attempt to enter the market will bring prices and profits tumbling down. A more defensible strategy for the dominant firm is to be content with more modest profits and minimize competitive threats.