So you have two choices about the shape of hole you start with.
You can either dig a hole that's broad but shallow, or one that's narrow and deep, like a well.
The very best startup ideas tend to have three things in common: they're something the founders themselves want, that they themselves can build, and that few others realize are worth doing.
Nearly all good startup ideas are of the second type. There were only a couple thousand Altair owners, but without this software they were programming in machine language. Their first site was exclusively for Harvard students, of which there are only a few thousand, but those few thousand users wanted it a lot.When you have an idea for a startup, ask yourself: who wants this right now?Similarly for Microsoft: Basic for the Altair; Basic for other machines; other languages besides Basic; operating systems; applications; IPO.Self How do you tell whether there's a path out of an idea?Usually this initial group of users is small, for the simple reason that if there were something that large numbers of people urgently needed and that could be built with the amount of effort a startup usually puts into a version one, it would probably already exist.
Which means you have to compromise on one dimension: you can either build something a large number of people want a small amount, or something a small number of people want a large amount. Not all ideas of that type are good startup ideas, but nearly all good startup ideas are of that type.Google is an immense crater: hundreds of millions of people use it, and they need it a lot.A startup just starting out can't expect to excavate that much volume.Made-up startup ideas are usually of the first type.Lots of people are mildly interested in a social network for pet owners.Imagine a graph whose x axis represents all the people who might want what you're making and whose y axis represents how much they want it.