Life Is Complicated - Keep Your Software Simple - a Forbes article that's been making the rounds lately, is a rather explicit example of LESS being more.
The short version: Company launches product with a billionty features. Product fails. Company talks to users, who ask for fewer features. Company simplifies product. Adoption skyrockets.
The users were not using the product because it was simply too much – it did too many things – it had too many options. The number of options stressed the users out and they simply chose to stop using the system.
No kidding, huh? I hope the high profile of Forbes helps software developers and product owners get this message. (Bonus would be talking to the users before investing months of development time and scads of money in a product that didn't meet the user's need. But that's a story for another forum.)