This is less attractive when you realize that all big companies will have a non-European subsidiary pay a non-European component of facebook for all their advertising needs, which would hugely lower the revenue base that 4% is calculated from.
Legal concepts like "beneficial ownership" [1] and the definition of an "affiliate" under U.S. securities law [2] deal with this.
TL; DR When it comes to taxes, modern law isn't tricked by incorporated Russian dolls [3].
[1] https://en.wikipedia.org/wiki/Beneficial_ownership
If you're late to the party, which I think the majority businesses in and out of Europe are, means you have made other priorities.
Question is whether or not how hard they hit when GDPR goes live 25th of May. That remains to be seen, but it wouldn't surprise me if there's a `grace` period.