Imagine a tool that does lots of things, and another that does one thing really well. And imagine both of them are free. Long Tail theory suggests the specialised tool wins, right? No, maybe not. If the general-purpose thing does an okay job, many will prefer it instead. Why? Because there’s a premium attached to things that are predictable - if you’re already familiar with the general-purpose tool, because you’ve used it or heard about it from a trustworthy mate, you’ll probably try it first.
All this is the topic of Dan Bricklin’s new essay, When the Long Tail Wags the Dog. Examples he cites are spreadsheets (of course :-), word-processors, PDAs, email, cell phones, and cars. All of these products have more specialised substitute products available, but the general-purpose systems have prevailed because people are often more willing to bend them into the things they want, than enter the land of the unknown. You might not like KFC very much, but you attach a premium to it because you know exactly what you’ll get.