The document discusses passback tags, which allow an ad network to return an ad from another source when it does not have a paid ad to serve itself. A passback tag acts as a default ad that tells the system to try serving an ad from another connected ad network. The document provides instructions on enabling passbacks in ZEDO, generating passback tags, and implementing passbacks by giving the tags to ad networks and having them serve the passback tag when they do not have their own ad to provide.

2. What is passback?
 Passback or default tags can be any network or remnant tags
that you use to fill inventory.
 When advertiser’s tags don't have anything to serve (for
example, there isn't an advertiser willing to pay a high
enough CPM), we can send that impression back to ZEDO to
serve next ad in rotation.

3. What is the use of passback tag?
 Passback line items are used with third-party advertisers for a
number of reasons. Primarily, passback line items return a house ad
or other remnant ad within server when the third-party doesn't have
an ad to serve or when this ad doesn't meet the minimum CPM
agreed upon with the third-party.
 Before beginning this process, you should have generated a
passback ad tag in server to which remnant or house inventory is
targeted. The third-party should then take this ad tag and traffic it
in their network as the lowest-priority ad, one that will serve if no
eligible ads are found.

4. How it works?
 The passback tag acts like a default ad in the ad network’s system. If an ad
network cannot send a paid ad, it calls ZEDO’s passback tag, and the
passback tag tells the regular ZEDO Ad Tag to call the next Available ad
network.
 Say that you have Interclick and Specific Media set up in your ZEDO
account and you give them both passback tags. The process would
work as follows:
 A user views a page that either has a ZEDO tag on it or calls a ZEDO
tag through a 3rd party ad server.
 ZEDO’s ad tag calls Interclick Media, which fills the slot with an ad.
 On the second refresh, Interclick doesn’t have any paid ads so it gives
way to ZEDO’s passback tag.

5.  The passback tag notes that Interclick has no paid ads, so will not call
Interclick again (for that user in that 24 hour period); it will call the
next available ad network, Specific Media.
 This flow will continue through all your top tier ad networks that are
passback enabled.
 After the top tier networks have no paid ads to serve, ZEDO will give
the inventory (for that unique user, in that 24 hour period) to your
filler ad network.

6. Implementing Passbacks
1. Enable Passbacks in ZEDO
2. Generate Passback tags
3. Give the Passback tag to the ad network(s)
1.) Enabling Passbacks in ZEDO :
Preliminary requirement :
•Ad network Advertisers must be linked to the Ad Network.
 In the Create/Edit Advertisers page, select the Link to Ad
Network checkbox
 Select the ad network from the dropdown
 Enter the login details for the ad network account

7. Ad level requirements
•In the Create Ad UI, select the Enable Passback checkbox (at the
bottom of the Ad Details section).
 You don’t need to enable passbacks for Filler ad networks.
• The “Ad” in which you upload the ad network code needs to be
frequency capped in order for Passback tags to work
 You can set a cap of up to 99 impressions per unique user per
day. If you don’t have the ability to set a cap this high, please
contact support.

8. 2.) Generating Passback tags :
There are a couple ways to access the Passback tag generator.
1. Click the Generate Passback Tags button after creating or editing an Ad.
2. Click the Passback Tags button on the Campaign Dashboard .
In the Passback tag generator the Advertiser and Campaign will be pre-
selected. You may need to select the Ad.
You will see one Passback tag for each Channel the ad is targeted to.

10. 3. Give the Passback tag to the ad network(s)
<!-- Iframe tag:-->
<!-- begin ZEDO for channel: AT Homepage Top , publisher: AajTak WAP , Ad Dimension: WAP -
1 x 1 -->
<iframe src="http://d2.zedo.com/jsc/d2/ff2.html?
n=821;pn=821;6=533;c=1382/1269;pc=1382;s=6;d=51;w=1;h=1;$=1812786;pa=1812786"
frameborder=0 marginheight=0 marginwidth=0 scrolling="no" allowTransparency="true"
width=1 height=1></iframe>
<!-- end ZEDO for channel: AT Homepage Top , publisher: AajTak WAP , Ad Dimension: WAP - 1 x
1 -->
<!-- Javascript tag: -->
<!-- begin ZEDO for channel: AT Photo Top , publisher: AajTak WAP , Ad Dimension: WAP - 1 x 1
-->
<script language="JavaScript">
var zflag_nid="821"; var zflag_pbnw="821"; var zflag_cid="1386/1269"; var zflag_pbch="1386";
var zflag_6="533"; var zflag_sid="6"; var zflag_width="1"; var zflag_height="1"; var zflag_sz="51";
var zflag_$="1812786"; var zflag_pbad="1812786";
</script>
<script language="JavaScript" src="http://d2.zedo.com/jsc/d2/fo.js"></script>
<!-- end ZEDO for channel: AT Photo Top , publisher: AajTak WAP , Ad Dimension: WAP - 1 x 1 -->

11. <!-- Javascript tag: -->
<!-- begin ZEDO for channel: AT ROS Top , publisher: AajTak WAP , Ad Dimension:
WAP - 1 x 1 -->
<script language="JavaScript">
var zflag_nid="821"; var zflag_6="533"; var zflag_width="1"; var zflag_height="1"; var
zflag_sz="51"; var zflag_$="1812786";
</script>
<script language="JavaScript" src="http://d2.zedo.com/jsc/d2/fo.js"></script>
<!-- end ZEDO for channel: AT ROS Top , publisher: AajTak WAP , Ad Dimension:
WAP - 1 x 1 -->
Smart Tag:

13. 1. A page makes an ad request to DFP for an ad using the DFP ad tag on the
page.
2. DFP returns a line item containing third-party code.
3. The page uses the third-party code to make a request to a third-party ad
server.
Non-passback scenario: If a matching ad is available, an ad is served from the
third-party ad server.
4. If no matching ad is available on the third-party ad server, the server
returns (i.e. passes back) the DFP ad tag that you have provided your
third party.
5. The page makes a second ad request to DFP using the passback tag
contained in the third-party ad.
6. A house ad or other specifically targeted line item is returned from DFP.