The major tech companies impacted by the law are already likely taking steps to comply. Is anyone seriously saying they’d rather just wave goodbye to an entire continent?
If your website accepts Euros, has multiple european languages (e.g. spanish, german, etc.), you do marketing in Europe, then we can conclude that you legitimely do business in Europe, you are then required to be GDPR compliant. This is indicated in one of the GDPR article (can't remember which one)
Edit: fix typos
Quote from GDPR, page 5, recital 23 (http://www.privacy-regulation.eu/en/recital-23-GDPR.htm). I'm no lawyer, but that's the way I'm understanding it.
Yet, that is only one of two reasons why you would be subject to GDPR, the other is "the monitoring of their behaviour as far as their behaviour takes place within the Union".
As far as I can tell, logging a european IP address together with urls (i.e. an access log like every server has) would qualify you even if you aren't doing business there.
Completely unenforceable though.