not realy an answer to your question , but ...
quote from clients email
We also sold a 4k painting through an art group email and a 7.5k
painting through the website which was great.
the group email is exactly that. Not 100% sure why people sign up to her newsletter. It's just a normal 'newsletter' signup. Still, it proves that it works.
I'm revamping their site as it happens, and see that they have just under 700 sign ups in the database. That is over 20 months.
Up until now I have just left them to manage it themselves, emailing from Outlook in their office. I have however said that we could install phplist http://tincan.co.uk/phplist
Does anyone use it ?