RTB bidders are actually throtled based on the amount of traffic they purchase.
For example, if you win on average 100% of the time, you will get to see 100% of the traffic (for example, third-parties can see 100% of YouTube views, know which IP block has seen what videos, etc).
However, if you win on average 1% of the time, you may get only 1% of the requests.
Usually it's proportional to the amount you buy, to prevent such passive data collection.
Regarding proportionality, don't they always get the info of the bids they win? If so, what you're saying is that you only get the info of bids won.
Yes
> If so, that would give all data to any bidder, as claimed above.
No, the big networks like Google or BidSwitch (which is an aggregator of traffic from other networks), they send you a randomized % of the requests.
The more you buy ("win-rate"), the more this % increase (so the number of requests per second you are allowed to receive.)
Some networks don't care or are too small, so they send you 100% all the time.