Suorces of revenue (offline) in apps?

[denbbco72]

I'm looking into building an app, but I'm not sure if the revenue for my idea would be worth pursuing.

I've read articles that describe 6 basic methods to make money:

1. In-App Advertising (Free with Ads) - Most commonly seen in smartphone apps.
2. In-App Purchases (Selling Virtual or Physical Goods)
3. Freemium (Gated Features)
4. Paywalls (Subscriptions) - Being similar to Freemium, the content instead of the features are locked.
5. Paid Apps (Pay money to download)
6. Sponsorship (Incentivized Advertising)

I assume advertisers for your app are normally found when you sign up with companies like Taboola. But what about offline advertisers? Are there companies that specialize in them? If not, how would I bill them?

Thanks in advance for any help or knowledge you can provide.