I really liked his idea that the users teach you about what you've made. That's a really great philosophical point.<p>I think his comments about open source are interesting and how he's never seen anybody open source too much. I humbly disagree, I've definitely seen a few startups get nowhere because they ended up open sourcing their entire product, meaning nobody needed to pay them for anything.<p>There needs to be a strategy for open sourcing your code...for example if dropbox open sourced their client, they'd still own the relationship to their storage back-end and act as the broker for that data. Their client isn't really worth anything anyways...so it doesn't really matter.<p>But let's say Microsoft open sourced Office and Windows. Okay, now where do they make their money? They're pretty much just left with services work, and services and support often only exist if the software has problems. Anybody else can then come along and code away their services business by fixing bugs, making better interfaces etc.<p>Open sourcing needs to have a valid business strategy and it can't just be putting your company's investment up on github because that feels good.