If I'm on the titanic I want to be steering.
The biggest motivation is not the money but the impact.
Akismet started on a $70 dollar-a-month server. Anyone can scrape together $70.
I don't have big ideas. I sometimes have small ideas, which seem to work out.
People might start with LiveJournal or Blogger, but if they get serious, they'll graduate to WordPress. We try to cater to the more powerful users.
From the first time I held an iPhone, the space has evolved quickly, and people have shifted from reading content on their desktops to smartphones and iPads, even long-form stuff.