I believe this can be done by duplicating your sheet. i also answered for someone similar to your case, you can find with attachment on that thread: Try to calculate price keeping one item within a dimension constant
Sorry, i couldn't deeply go through your file currently but if no one replies, I try to look at it later tonight. Thanks
Thanks Matt! (Sorry for my slow reply, I'm on UK time.)
That's a really good question. There isn't a 1-1 relationship between an open and a click - you could have one open and multiple clicks.
Also, I didn't include this in my simplified data, but you could have one open and no click.
My aim is to get a click to open rate - so out of 100 opens we might have 30 clicks on M1, 20 clicks on M2, etc. - and I want to display as a percentage.
Does that answer your question? :S
Update: Thanks for the link, but I'm not sure I understand how I can use that solution for my problem.
I have duplicated the data source, used the unique identifier as the linking field, but it doesn't seem to have made a difference to my viz.
I'm probably missing something!