While our focus was on the hidden costs of line extensions, several respondents, including Laura Wicke, emphasized how poorly planned line extensions can incrementally diminish a brand’s equity without this effect being noticed until it is too late. Alexander Biel correctly pointed out that consumers can forgive and forget if weak line extensions are withdrawn promptly. However, as John Balson observed, many companies lack the motivation and the cost data needed to separate the successes from the failures clearly, and few prune their product lines as aggressively as they add to them.