this is really good advice about ownership shares in a startup company.
But the advice is also very general. E.g. in the startup phase developers are extremely important - without them - there is no product. On the other hand; once the product has shipped past the first few updates and feature additions, and when the code is clean and prooved scalable - how much time does e.g. a two man developer team normally spend maintaining e.g. two mobile apps (iOS and android) plus a website?
I suspect that the developer-time is decreasing as the company gets succesfull (facebook would seem to prove otherwise as the keep hiring), while the the biz people will spend more and more time administrating, monetizing etc.
What is your experience - and should this in any way reflect on ownership shares between different kinds of expertise, maybe even vesting agreements?
As a developer, I can honestly say that the work never decreases. If you're developers aren't doing anything, then your business isn't moving forward.
It doesn't matter if you have the best app in the world; if you're not updating it, providing new features, and releasing new apps, then you will be outdated just as fast as last weeks milk.
As an entrepreneur and software engineer, i would say that you should always keep developing new features, improving interfaces, etc. or else your company will "die".
Take Microsoft as an example, they release a new version of Office every 2 years.... does this mean it's a complete new Office? No... sometimes they just arrange interfaces or screens (95% of the new release was part of the last one) but they must keep the pace.
As Craige said, work never decreases... because new trends keep popping up, people/clients change, market's needs change, etc.