Settings for Email Opens in the Smart Campaign setting

[WY]

Dear Marketo Community, 

I would like to get some advice on this particular setting in the Admin panel, please. 

At present, this feature is disabled in our instance. Could someone explain in detail the differences between having this toggled on versus off in the email open metrics?  

Thank you 
Wayne

[Michael_Florin]

I've never seen that setting before. Where exactly did you find that?

But the idea is obvious, right? If you send one email through two different Smart Campaigns, the opens for each Smart Campaign are being tracked separately. Makes some sense to me, although I never considered this to be an issue. Most likely, because I usually don't send one and the same email via two different Smart Campaigns. And if I did, I would have assumed that separate tracking would be default anyways.