Admob House ads Help

1)I want to know what is house ads in admob?
2)Can i promote my own app in house ads?
3)is there any charge for house ads if user click or impression generated?

Please help me

  1. A house ad is where you can cross promote your apps within each other. With AdMob mediation you can choose to show these house ads sometimes in place of standard ads.

  2. Yes

  3. No there is no charge for house ads. This a free way to promote your own apps. However, in a round about way it still costs money to show these ads because you will be losing revenue from the ads that could be showing in place of your house ads.

Thanks for explanation

More is that admob allow you to sell ads to “another advertiser’s product through a direct deal” but i don’t try it yet.
https://support.google.com/admob/v2/answer/3210452?hl=en