Invalid Formula Blended Data
In trying to create a formula using blended data, I'm getting "INVALID FORMULA" from Google Data Studio (GDS). I've noticed that my Google data shows up as a Blue field, while my Supermetrics data shows up Green. Not sure if this matters. Please help me understand why I can't create this "simple" blended formula for clicks, impressions, etc. I've attached a screen shot just in case it provides better clarification.
I'm working from Jeffalytics YT video building the ultimate PPC Report. It's about blending data sources for a more complete GDS report. It's a great video really...better than the other 4 I've watched trying to learn about GDS and blending data. Don't know why this step by step instruction works for him and not for me. Ugh. :/ It's gotta be a user error, but I can't seem to figure it out.