The only catch? Eroda doesn’t exist. It’s completely fictional. Musician/photographer Austin Strifler was the first to notice, bringing attention to it in a long thread that unraveled over the last few days.
The creators of the Visit Eroda campaign covered their tracks well. According to Baio, they didn’t leave any identifying information in image metadata, domain records, or in the site’s markup.
I verified a connection between @visiteroda and @Harry_Styles. The Eroda page is using a [Facebook] pixel installed on http://hstyles.co.uk. You can only track websites you have control of. They are related.
I’m not arguing that a promotional campaign for Harry Styles’ new record should be taken as a serious privacy violation; I am, in fact, quite sober. But I think there’s a lesson in the campaign’s difficulty for identifying data to be completely disassociated. A need for behaviourally-targeted advertising is what ultimately made it easy to reassociate the anonymous website.
See also: A 2011 article by Andy Baio in which he describes how he was able to figure out the author of an ostensibly anonymous blog because of a shared Google Analytics account.