Was there ever a time, even in the early days of the store, when making a shitty app would automatically bring in primary income?
As the competition has increased, you either find dozens of clones of the low quality apps, or one or two competitors that have taken most of the market.
I disagree that the app store gold rush is completely over however - I entered a crowded space with established competitors (including each school's own app, Google Maps, Apple Maps, GuideBook, Blackboard, and many more, and am still able to carve out a solid niche for myself.
The trick is in not only providing value with the app, but having a scalable marketing strategy. Treat it like any other product you want to sell, don't ride the Appstore-luck wave.
I've been hesitant on monetizing because of that very same growth I'm seeing. In about 6 weeks I expect to peak in the top 10 US Navigation app for about 3 days (new school year).
I've been debating ads + freemium "ads free mode", but I feel that at this point I'm getting more value out of establishing a user base. My real issue is that I don't have a GOOD scalable monetization option in mind.
Negotiating local deals takes way too long with too much turnover. I'd be interested in offering school apparel deals though. That seems scalable with the right vendor.
e: I am currently split testing one campus @ 99 cents in a separate app to test how that's received.
Don't build a business, create something good.