Each campaign can have several ads associated to a same space. At the same time, several campaigns can be associated with this space, making that, in the more general case, when you open a page that contains that tag, e-planning will have to decide what ad of which campaign shows.
This document explains the mechanism e-planning uses to take this decision based in the characteristics that were given to each ad and each campaign.
First, e-planning decides which campaign is going to be shown (between the ones that are associated in this space). If none of them is in conditions to be shown in this space (for example because they are all configured to show only to argentine users, and you entered in the page of another's user country) so it shows a house ad associated with this space. If there is no house ad associated with this space , it shows a gif transparent ad.
Once the system have decided what campaign is going to be shown, e-planning choses between the ads of this campaign that are associated with the space.
For each campaign that is active and associated with the space, e-planning checks if it is in conditions of serving a ad in this space.
This way, the CPM (Cost per mille, sold for amount of impressions) campaigns are descarted, the ones that have run out of all their impressions and the CPC (Cost per Click, sold per amount of clicks) campaigns that have already recieved all their clicks.
It also checks that the particular user whose navegator makes the request has not run out of the amount of impressions per user or per period of time or per sesion that has been accorded. If the campaign is configurated for not showing any more to the users that have already clicked in a ad, and it is a user that is in that situation, the campaign is also descarted.
Campaigns that do not comply with the filter conditions will be also descarted (for example: if the IP direction of the user is in a country in which it must not be showed).
Campaigns are also descarted when they have no associated ads with the space, although it is associated with the space.
Once they are all discarded, e-planning examinates the campaign with priority 1. Only if none of this is in serving condition, the priority 2 will be examinated, and only in case that none of the priority 2 is in conditions, there will be examined the ones of priority 3, and so on.
Between the ones that remain of priority 1 (or priority 2 if those are out, etc) the weights are compared. The weight is a percentage that indicates how many impressions from the total of each space must correspond to each campaign. But it is not necessary that the weights of the associated campaigns to a space add up to 100. For example, if there are two associated campaigns to one space and you wish that one reaches the 80% of the impressions and the other one the 20%, you can asign them weights 8 and 2 respectively, but you must be careful, because these same campaigns may be associated also with other spaces where other campaigns are running, each one with it's weight, and then, in this spaces, even if the impression proportion between these two campaigns will remain being from 8 to 2, there will no longer be 80% and 20%, because the other campaigns will also use a percentage of the impressions.
Once the system choses the campaign that will be served, a ad from that campaign is chosen to serve. For this, e-planning choses, between the ads of this campaign, the ones that are associated with this space and are from a format that allows it to show, according to the tag that made the request (for example: if it is an image tag that can only show GIF and JPG ads, the Flash and HTML are descarted).
Between these ads, the ones with a heigher priority are taken. (Meaning the one that has the smaller priority number). In case there are two ads with the same priority, e-planning considers the weight.
The weight is the percentage that indicates the amount of impressions of this space from the total that must correspond to this ad. But it is not necessary that the weights of all the associated ads of a space add up to 100. For example, if a space has two associated ads, both with a weight of 25% (adding up to only 50%) e-planning will asignate them a real weight of 50% to each one. In this way, the fact that they have equal weight is respected, but the now add up to 100. Similarly, if one has weight 50 and the other one 100, e-planning will asign them real weights of 33 y 66.