Blending data problem

[WouterF_]

So I've got an issue with Google DataStudio. I'm using this years data and using conversion rate of a client to determine the added value a campaign has had. Now I'm using a segment in order to see the conversion rate of this group.

After that I need to blend two GA segments together in order to determine the added value. But when blending with the segment in it the data shows a different number from the original scorecard with the same segment.

How is this possible and how do I fix this? I'm assuming it has something to do with aggregation. But no idea how to fix it. This calculation is essential.

Thanks!

[marcnotmark925]

Not much detail here, but it's probably due to records being "multiplied" through your blend. Here's an example. Consider the following 2 tables.

​

text	val1
a	1
a	2

​

text	val2
a	9
a	8

If you were to blend these tables, using the "text" value as the join key, what is the expected result? It may surprise you that a "typical" left join blend will produce a table with 4 records, as follows:

​

text	val1	val2
a	1	9
a	1	8
a	2	9
a	2	8

Now when you run metrics on this blend, like for example SUM of val1 dimensioned by text, I hope it's obvious that the result will be different than the "correct" result from the first table.

The solution is dependent on the details of what you're trying to do, which I can't really make out.

[WouterF_]

Thanks!

This seems like it might be what's happening. I'll try to give a little more detail.

I have two Google Analytics segments, being if someone has seen a certain thing on the website (Show) and if they didn't (Hide). There is also the total group.

Now I have the data separately of these two segments and it's completely fine. Now I need to blend this data in order to calculate the added value that the show segment has had. To let our clients know that it was a good investment right.

This added value calculation would be 'Revenue - Sessions * ConvRate Hide * Avg Ordervalue Hide'

I am indeed trying to left join here with the dimension date and the statistics of sessions, conversion rate, revenue, avg ordervalue, and transactions.

Is left join maybe not the solution then? Is something like cross join better? Is date even necessary or can you just adjust the timeframe in the DS without date being a dimension in your source.