Back from working at a charity stall at Glastonbury, signing people up to our climate finance-based petition.
After collecting hundreds of email addresses, just have a quick thought I'd like to share. The majority of people supplied a yahoo or hotmail address, and many of these took the form of a nickname, a joke or a cultural reference. Things like [email protected], [email protected], [email protected] (I've made those up, but you know the deal. You've got one too; you made it up when you were in the horrid fog of adolescence). These accounts, most likely set up many years back, have over time probably been placed on loads of mailing lists and is now the user's default 'junk' account. So they don't mind signing up to stuff that'll bring more emails they're not hugely interested in, cos that's the purpose of that account anyway. While these lovely people were happy to sign up and provide their details, they might be viewing any emails they receive as more or less unimportant: thats why they've directed it to an account started many years ago.
A smaller group provided a gmail account. These addresses, almost without exception, took the form of [email protected]. Very few people had a 'veryslightlymental'-type address with gmail (or have FirstnameSecondName@hotmail). Gmail addresses are much more formal. If people use their real name, then its reasonable to assume they use this account for more important stuff (cant put [email protected] on a CV, for example). So these addresses might be for work, or for use on official forms, or to share with figures of authority like grandmothers and potential employers.
This is all obvious. Let me quickly approach my point. People that sign up with a more formal email address are, maybe, treating the future emails as more serious, or more important, than those who sign up with an old retro '90s account. So there's a hierarchy. Signing someone up on their formal address (usually gmail) means they'll treat your send-outs with a bit more respect. This might even translate to higher open rates, clickthrough rates and increases in harder-to-measure metrics like awareness and engagement.
Just as salespeople are always eager to get a phone number for you instead of an email address (cos you can easily ignore their email), it's probably not too long before salespeople (and charity workers) say stuff like, 'Instead of your hotmail, can I get your gmail?'