In-app advantages:

• No bans: Avoid the constant ad account, payment, and creative bans common on Facebook. You can use more aggressive creatives and landing pages.
• Longevity: A well-set campaign can run for 1-3 months without constant tweaks, especially on iOS.
• Less routine: Frees you from daily platform battles, allowing focus on creativity and optimization.

In-app disadvantages:

• Limited targeting: You can’t target by gender, age, or interests, only by app category or specific publisher whitelists.
• Variable traffic quality: ROI and user quality can be low in some regions.
• Complex setup: requires testing many hypotheses and experience to find a winning combination.

Key to success:
Success hinges on the right combination of:

• Offer
• App (with proper tracking/design)
• Traffic source
• Video creative
• Optimization strategy

Audience & scaling:
The audience consists of users within mobile apps (games, utilities, finance, etc.). You build whitelists of profitable publisher apps from your test data to scale effectively.

Final takeaway:
In-app traffic isn’t a magic bullet, but it offers stability and creative freedom. With the right setup, you can achieve 60-80% ROI (even 300%+), providing a powerful, scalable alternative to the volatility of Facebook.