Yes, I can't find the episode now, but on the 37signals podcast, Jason and DHH said that driving signups with public writing are part of their job that they owe

Yes, I can't find the episode now, but on the 37signals podcast, Jason and DHH said that driving signups with public writing are part of their job that they owe to their employees, and that includes presence on places they don't really like such as Linkedin.