If you've imported your Google Ads cost data or other cost data into your Analytics account, you can see that data in additional columns in the Model Comparison Tool. If you haven't imported any cost data, the columns will not appear. In the Spend column, you'll see the total spend for the date range you've selected.
Choose either Conversions & CPA or Conversion Value & ROAS from the metrics drop-down selector in the table to display the corresponding cost data metrics for each attribution model you've selected. CPA (cost per acquisition) is calculated by dividing the channel Spend by the count of conversions attributed to a channel under a particular model. ROAS (return on advertising spend) is calculated by dividing the Conversion Value (based on Ecommerce Revenue or Goal Value) by the channel Spend.
In the % change column, you see the percentage that the selected metric differs across attribution models. Because ROAS is a calculated metric based on Conversion Value, its % change between models is identical to that of Conversion Value and is not shown in the table.
Each numerical percentage in the % change column has a symbol next to it:
- A gray dot indicates that there’s no identifiable change between the reference and comparison model, i.e., the two models value the marketing activity in the same way.
- An upwards arrow indicates a positive shift away from the valuation of the reference model.
- A downwards arrow indicates a negative shift away from the valuation of the reference model.
If the absolute value of the difference between attribution models is 10% or larger, the arrows are also colored to indicate whether or not the shift is favorable.
- Green indicates a shift in favor of the comparison model, e.g., a decrease in CPA under the comparison model. An increase in the number of conversions would also be indicated by a green arrow.
- Red indicates a shift in favor of the reference model, e.g., an increase in CPA under the comparison model.
The meaning of "0" and "—" in table entries
Both "0" and "—" (em dash) may appear in the Spend and Conversions columns.
- "$0.00": cost data is available for a given channel, source, medium, keyword, etc., but the total spend for the selected date range is $0.
- "—": cost data is unavailable, e.g., if you have not uploaded cost data, or it is a channel without cost, such as Referrals.
- "0.00": the selected attribution model gives no conversion credit to that table entry for the requested date range.
- "—": conversion path data is unavailable for that table entry.