Great article from DHH:
A more common case is that you can get 80% of the feature for 20% of the effort. Which in turn means that you can get five 80% features, improvements, or fixes for the price of one 100% implementation. When you look at it like that, it’s often clear that you’d rather get more done, even if it isn’t as polished.
I would love to find a way to convey this more efficiently to clients, especially when writing project proposals. It should be noted that it can be tough to convince clients that a 80% feature actually answers all of their core needs when they have a 100% feature in mind.