Closed Systems are not eco-Systems
Ok, maybe this fact needs to be impressed into people before they enter YCombinator or whatever pipeline out there is pumping this type of company out, but:
Closed Systems are not Ecosystems
Regardless of what closed system you examine, whether it be the App Store or Facebook, or Twitter, if you are hitching your business plan onto one of these, you are essentially dooming your company to eventual extinction.
You don't even have to be an MBA to misunderstand this - if your business model siphons value from the ecosystem, where 'value' is defined by the host of this system, then you become a threat to the host who then responds to your company as a parasite.
There is simply no other way to see this.
Your company or project is a parasite to the host.
This works across not only technology systems but ideological ones too. With all due respect to Dr. Stallman, this same dynamic is operative with the GPL - you have a set of constraints you impose on anyone entering or interacting with your system, anything that eventually becomes successful will by simple physics come into violation of those constraints.
In the case of the GPL, even though the intentions were good, a project will be doomed to stagnation due to the simple fact that those who don't or can't buy into the manifesto (for ANY reason) are prevented from contributing value to the system.
In the case of this second-order derivative cottage industry springing up around these social media companies, the dynamic is exactly the same - how could you possibly justify making money at the expense of your host without expecting pushback? These social media companies are hemorrhaging investor cash like there's no tomorrow, their investors would scream bloody murder if a company was able to monetize Twitter's data when even Twitter itself can't do this.
The moral here is clear:
If you love something, set it free. Write useful, permissively licensed open-source software against open API's - build for the future and not the past.