Even if they're doing that it's relatively easy to find what postal code a bunch of British citizens live in (e.g. start with famous people whose primary residence is often well-known). I filled it in with "Fake McFakety" or something like that in a random postal code in London, so I wasn't even trying.

They're not going to have a known fool-proof mapping of names/postal codes to something that's guaranteed to be that person's current E-Mail address.

Which, in the age of allegations of say Russian interference in elections[1] means this sort of Internet poll is always going to be suspect.

It doesn't mean it's completely useless, it's some general way of gauging interest for sure, but the GPs suggestion was that something would change once it passed the 33 million mark. I don't think you can make that claim with a poll that's so easily gamed.

1. https://en.wikipedia.org/wiki/Russian_interference_in_the_20...