Why house ads, more apps buttons, push house ads are not useful any more...

I have 80k active users in house ads (i’m not adding new apps to system anymore, it’s worthless), what is giving mostly … 40-50 installs from:
-intersititial
-push house ads

What I observed in CPI campaign, not house ads:
…9mln impressions
300k clicks
30k installs

So if you display your house ads, to achieve the same results you need to have mostly 1mln users who receive your ads 9x times to get just 30k installs.
I think it’s worthless and even with these 30k installs, organic downloads dropped after campaing end.

To get 30k installs in appbrain, you need to have $6000 or $3000 in ayetstudios, it’s a lot but build house ads system with 1mln active users, manage servers, etc.

With app when I had 15-20k DAU, I have only 100-300/day who is clicking more apps button.