DHH on Signal v. Noise:

What’s good for platform makers is often not good for those who build upon it. That’s where the whole picking up pennies in front of a steamroller comes from. Yes, a few may be quick enough to pickup enough pennies to fill a jar, but for most, it’s not a wise trade of risk vs reward.

Forget the paid app.

There are a few examples of companies breaking the mold and creating great app-based businesses on mobile, but unfortunately they are the exception, not the rule.