The Creeping Featuritis Chart
Although often associated with marketing, sales, or program management roles, developers are not immune - and when it infests code, it's an insidious sort of product rot, reducing useful software into heaps of expensive widgets and aggravating help features.
The Agile focus on customer-valued features is supposed to prevent this... "agile enables you to build the right software at the right time". But teams sometimes forget: they must consistently practice customer prioritization to be innoculated.
On Peter Abilla's blog, a chart by Kathy Sierra, The Featuritis Curve, captures what this looks like from the Customer's point of view. The author reminds us to "focus on the customer and abandon the competitor-focused strategy all-together." Clearly a visual thinker, he goes on to discuss the Pareto Principle (a.k.a the 80/20 rule), a Prioritization Matrix and the Agile Manifesto.
Abilla, a former Amazon.com employee also mentions the Amazon core value of "customer obsession".