I work in e-commerce and this kind of thing is totally standard. You get salespeople trying to sell you this and much worse regularly.
I was once pitched the exact dark pattern as in the OP - covert email collection. I was gobsmacked. I wrote about it at the time thus:
> Towards the end of the slide deck, Dom excitedly explained how if a user enters an email address in any form field anywhere on the website, then regardless of whether the form is submitted, that email address will be captured by IntegriMart and paired up with a browser fingerprint for that user. This, presumably, allows us to “continue to build a dialogue” with that user.
I was once pitched the exact dark pattern as in the OP - covert email collection. I was gobsmacked. I wrote about it at the time thus:
> Towards the end of the slide deck, Dom excitedly explained how if a user enters an email address in any form field anywhere on the website, then regardless of whether the form is submitted, that email address will be captured by IntegriMart and paired up with a browser fingerprint for that user. This, presumably, allows us to “continue to build a dialogue” with that user.
Full story for those interested: https://www.michaelbromley.co.uk/blog/the-covert-opt-in/