MoPub parallel requests

[tacchan23]

While reading the MoPub best practices https://developers.mopub.com/docs/mediation/waterfall-latency-and-best-practices/ I found this:
Keep items at the same priority: If you set up items at the same priority, then MoPub Marketplace, S2S networks, SDK networks, and direct-sold ads can compete with each other for the maximum CPM. We are obligated to show a network creative anytime we reach out to a network and it successfully returns a creative, so we have to wait until both Marketplace and your network partner have returned a result. Parallelizing requests by having items at the same priority improves your latency and CPMs.

Does it mean that I should keep, for example, 2 different Networks at the same eCPM level? what will happen in this case? both requests will happen at the same time? how MoPub will choose which Ad to show?

[codinami]

Hi @tacchan23!

Whilst we recommend to keep items on the same priority (i.e. P12) we don’t recommend to have two networks with the same eCPM unless that is their real-average eCPM.

Note Network eCPMs in the MoPub UI serve two functions:

1. prioritize networks within a priority
2. inform Marketplace Exchange of the highest network eCPM. This is the eCPM the exchange has to beat to serve an ad.

Also note, we recommend to set MPX price floor to what the lowest network partner is paying in each priority. This way the Marketplace can compete with each ad source and increase your overall eCPM. Example: set MPX-P12 eCPM to $0.05 to compete with all your networks if your lowest network eCPM is 0.05$.

In the case two networks have the same eCPM, one of the two will be randomly picked.