I won't be too specific, but in the thousands of apps, and enough to support a team of 6 people (we're entirely bootstrapped).
Is there a bias toward a specific industry or application type among your paying users?
Not really, as long as it’s a data driven app (and not a platform game...). About half of our paying users build startup-type, customer-facing products, while the other half is small businesses building internal management tools (like invoicing, custom CRM, etc).