Well, 'talk to your customers' is a little different from 'listen to your customers and make sure you understand exactly what problem your product/service solves for them'. And I think the only difference between evolution (as you've described it) and validation is that seeing how people use what you build, and getting qualitative data on those users is emphasised, rather than something that just happens over time.
At a minor level, that could be making sure that the next feature you implement is the one that will make your software much more usable from their point of view, rather than the shiniest or most technically interesting to implement. (e.g. it doesn't matter if your mousetrap automatically telling your computer when it's caught something, if their local mice just aren't interested in $bait_that_works_best_in_bobs_house )
On the larger scale, if your customers are using your product to solve a problem you didn't expect, you can't optimise your product so it sells even better. If the largest user of your mousetrap is the gremlin-catcher's guild, then perhaps you need to look at building more gremlin-specific features, and changing your marketing a little.
And, of course, the simplest metric for validation is that if they ain't buying it then it ain't doing what they want enough for them to pay for it.
Disclaimer: I have never run a startup, let alone used these principles. They just seem to make sense to me.
At a minor level, that could be making sure that the next feature you implement is the one that will make your software much more usable from their point of view, rather than the shiniest or most technically interesting to implement. (e.g. it doesn't matter if your mousetrap automatically telling your computer when it's caught something, if their local mice just aren't interested in $bait_that_works_best_in_bobs_house )
On the larger scale, if your customers are using your product to solve a problem you didn't expect, you can't optimise your product so it sells even better. If the largest user of your mousetrap is the gremlin-catcher's guild, then perhaps you need to look at building more gremlin-specific features, and changing your marketing a little.
And, of course, the simplest metric for validation is that if they ain't buying it then it ain't doing what they want enough for them to pay for it.
Disclaimer: I have never run a startup, let alone used these principles. They just seem to make sense to me.