You have to register with an ad network that allows segmentation. I know that InMobi and Playnomics give you that option. Then you register your app and integrate the ad network SDK into your app.
Once you've done so, you'll get the options to start campaigns(and a lot more!) in your dashaboard.
I work for InMobi so if you need any help at all with starting an ad campaign, do let me know :)
I have a Political Punjab related website which stable on fifth page on SERP i have use many way to promote my website but i am anable to get the result please suggest me what should do i to promote for my website and how can i get ...