Our company operates on a global level. Is it required to split our EU leads into a European workspace and a North American workspace?
No it's not, at least not that directly.
The issue of where the data is located cannot be resolved by lead partitions. It's about knowing in which Data center your data is located. There a few very good articles in the community on safe harbor :
Safe Harbor Program Update
Update from Marketo on the EU-US Safe Harbor Framework
What is the impact of this for those of us that operate a GLOBAL Marketo instance?
Now, you may want to use different workspaces and partitions based on geographies so that you can manage easily different unsubscribed policies (per your other question), langages, etc...
Usually the reason to have Workspaces is to divide leads and assets between BUs or groups that should be separated. Common scenarios
As Greg said, this has zero to do with privacy rules and I would not necessarily design Marketo WS on that principle. Each WS can use separate privacy workflows to comply with local laws, although I recommend adhering to the strictest country's email rules.
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