Prebid setup with bidders which have different currencies

Question

I have a simple Prebid setup with 2 bidders. I donot use "Send all bids to the ad server" feature. So Prebid works RTB with returning bids and sends the winning bids to Google Ad Manager (GAM) with key/value pairs like:

hb_bidder=bidder_A
hb_pb=0.10

hb_bidder=bidder_B
hb_pb=0.20

Off course there are line-items defined in GAM with the key/value pairs with those values above.

There is no problem in this setup, if all bidders use same currency.

What if bidder_A bids in USD and bidder_B bid in TRY Line items' currency of bidder_A were set to USD Line items' currency of bidder_B were set to TRY Note: It's possible to use different currencies in GAM 360)

Scenario:

1 USD = 8 TRY

Bidder	Bid	Currency
A	1	USD
B	5	TRY

In this scenario, bidder B wins which is wrong. Currencies donot affect prebid RTB if I am not wrong. When I checked the GAM request, it verifies me.

When I use Prebid Currency Module; it converts USD to TRY (1*8=8) for bidder A, and in this case winner is bidder A which is correct one. Prebid Currency Module fixes the RTB problem but Prebid sends converted bid hb_pb=8 (TRY), hb_bidder=bidder_A to GAM. In GAM side, line items of bidder_A defined with currency USD not TRY. So bid matches wrong line-item.

"Send all bids to the ad server" maybe solution but it's needed too much work.

I know, it's very complicated case, what do you suggest to fix problem?

Answer 1

While setting up Prebid Currency Module, there's a configuration parameter adServerCurrency which should match your ad server (usually GAM) currency setting.

In GAM side, line items of bidder_A defined with currency USD not TRY. So bid matches wrong line-item.

So in this case, you need to set adServerCurrency to USD because GAM line items are defined with currency USD.