The ‘pro iOS apps’ I mean here are the ones — like Mail Pilot and those that Panic tried to sell — that are sold to customers for their own sake; the app itself is the product, and it is paid for in the App Store.
Throttle on the other hand, much like the Facebook or Evernote iOS apps, is a companion app for a service whose business model resides elsewhere. I was not referring to these apps.
What we’ve found is the former (paid pro-level iOS apps) is not a workable business model. The latter, however, is a great thing — augmenting a service (paid or not) with an iOS offering has proven to work quite well for ourselves and others. This is what we’ll focus on in the future when it comes to iOS apps.
I think Apple recognizes this is the case, too, as they just launched in-app SaaS subscriptions last year, and are requiring all apps (such as Throttle) to use it.