Offline Measurement Protocol and Campaign Analysis

When sending Google Analytics Measurement Protocol the GA client ID (and custom generated user ID if applicable) are recommended to connect the online and offline activity. If the GA client ID can be collected and sent in the Measurement Protocol Hits, it is not required or recommended to send additional campaign information. Sending campaign data (in addition to GA Client ID) again in the Measurement Protocol Hit may create the following negative results: 

• A new session will be started even if the hit is sent within 30 minutes of online activity
• Campaign reporting will become inaccurate with additional sessions attributed
• Advanced attribution funnels and MultiChannel Funnel reporting will be inaccurate and attribute two campaign parameters 
• If manual campaign parameters are sent this will additionally disrupt benefits of auto tagging like revenue reporting back into Google Ads

 
If the offline hits occur after 30 minutes (the client ID is shared between online and offline) then the offline hits will trigger a new session with a ‘direct’ channel (and noted as such in the ‘Acquisition > All Traffic > Channels’ report. However, the shared client ID will ensure the two sessions are connected and any associated Google Ads auto-tagged campaign can be analyzed with ‘Last Non Direct’ model (and others) in the ‘Conversions > Attribution > Model Comparison Tool’. Furthermore In Google Ads reporting any associated auto-tagged campaign from the online activity will correctly receive the conversion credit and associated revenue. 
 
Note that in the rare case the Client ID (nor a User ID) cannot be collected/transferred as suggested then this offline Measurement Protocol Hit will not be associated with any online session/activity. In this instance it is beneficial to send campaign information to associate with conversion. 

For further illustration, please review the two example sequences below:

Recommended Setup: shared Client ID and no additional campaign parameters

Sequence: 

1. User clicks through an ad, arrives at the site with the autotag on the URL(A). The first pageview fires, starting a session.
2. User navigates the site, sends pageviews, and moves offline for conversion/purchase
3. Offline an MP hit is sent with the transaction.
   1. This hit has the same Client ID as the online hits from #1 and 2
   2. This hit does not specify any source/medium/campaign/adcontent/keyword values. All of those fields are all left blank
       

Analysis: 

If the offline hit (step 3) is sent within 30 minutes of the online hits (#1 and 2) then this will all be considered one session and the Acquisition > All Traffic > Channel reporting will associate the the conversion with the campaign. Other Attribution and Multi-Channel Funnel reports will be accurate. 

If the offline hit (step 3) is sent after 30 minutes of the online hits (#1 and 2) the the offline hits will create a new direct session associated (via GA Client ID) with the online activity. However, the Acquisition > All Traffic > Channel reporting will track this as direct and Conversion > Attribution and Multi-Channel Funnel reports will credit the original online campaign with the conversion through the 'Last Non-Direct' model. Clicks on the campaign will be accurate as well as proper sharing of metrics like revenue via autotagging. 

 

Campaign Data Sent in Measurement Protocol Hit

Sequence: 

1. User clicks through an ad, arrives at the site with the autotagging on the URL(A). Their first pageview fires, starting a session.
2. User navigates the site, sends pageviews, and moves offline for conversion/purchase
3. Offline an MP hit is sent with the transaction.
   1. This hit has the same Client ID as the hits from #1 and 2* (*see exception)
   2. This hit purposefully specifies at least one of these source/medium/campaign/adcontent/keyword values, which starts a new/second session(B).

Analysis: 

If the offline hit (step 3) is sent within or outside of 30 minutes of the online hits (#1 and 2) then the offline activity will be considered a new session as new campaign information is specified.

This is not ideal as it overwrites the campaign information, associates with new session, and inaccurately indicates two campaign clicks. These multiple campaign clicks will be recorded in Conversion > Attribution and Multi-Channel Funnel reports adding uncertainty on the campaign tracking information. 

Also note that in the step 3 if the campaign information is different from the original, not from autotagging, or in any way incomplete, this will further disrupt reporting like revenue import from GA to Google Ads (via autotagging and attribution). 

Exception: 

In the rare case that the GA Client ID cannot be transferred/shared between online and offline hits (see step 3.a.) then campaign details can be included in the offline hits for added context. In this scenario since the client ID was not available, we do not run the risk of overwriting any associated online activity.