Comment by dude123456

You get all the data (geo, user's year-of-birth, user interests, device type, etc) before you place the bid. All the json data fields are defined in the standard. I can see iOS and Windows-phone in the feed, it's not limited to Android phones.

https://www.iab.com/wp-content/uploads/2015/05/OpenRTB_API_S...

You don't actually have to bid.

(HN is rate-limiting me) edit: Data is pushed to you as fast as you can process it. It's a firehose.