Combine cost from different sources with blended data

[MPWebmaster]

Hello!

I am trying to set up a data blend where I want to combine and summarize the ad spend from Google Ads, Facebook Ads and Microsoft ads. Is this possible to do?

I have tried searching around on this subject and found different answers. Some says this cant be done and some says that it should be possible. I am able to set up the blend and get numbers from one of the sources at the time, but they will not combine. I have tried all the different Join data configurations and have seen some say that left outer is the only one that works. If this is true or not I m not sure. I know that name of dimension and metrics can differ from source to source, but I have even tried to change the dimension names in the data source to make them match each other. In addition to this I have also added the IFNULL formula to be sure that all sources gives me 0 instead of "missing data" or something similar.  Is there anything that I am missing regarding setting up this blend? Can this blend work with Looker Studio's own data blend function? If anyone has the answer here, it would be greatly appreciated. 

Thank you in advance. 

[a_aleinikov]

Hi @MPWebmaster ,

Yes, it’s possible to combine Google Ads, Facebook Ads, and Microsoft Ads costs using Looker Studio data blending, but there are a few key points:

• Make sure you have a common join key — typically a date field like Date.

• Use a Left Outer Join with one main source (for example, Google Ads) and blend the others onto it.

• Align the dimension and metric names across sources (as you’ve already tried — that’s good!).

• Use IFNULL() or COALESCE() to handle missing data properly.

If blending still fails, another option is to pre-aggregate the data in Google Sheets or BigQuery and then connect that to Looker Studio.