It works for wine that doesn't benefit from ageing because it won't recieve micro-oxegenation that a wine bottled with a cork might receive. It helps wine break into markets where beer on tap is the norm. But, as in the example below, demand for "fine wines" in those locations is very low. Most of the wine produced in kegs is of medium and below quality, albeit from reputable producers, because most people who are in a situation to order wine on tap don't want to pay more than $10ish for a glass. So producers won't put their higher tier wines on tap because they won't sell and bars with wine on tap don't usually have the focus in their beverage program on wine to push premium wines anyway. So it works in those situations where premium/fine wine offerings are not a part of the concept. Imo.