I've been working with propeller as an advertiser for over a year.

Traffic and convenience of the platform:
1. The traffic is quality, there is for any GEO
2. Several advertising formats
3. No targeting for Android devices, this is important to me
Support:
1. Instant response in the chat room.
2. In a month they assigned a personal manager
At night I have to wait for the manager's response about an hour (MSC)

I have tested many different advertising networks, propeller is the top in terms of traffic quality.