Well, I've investigated a couple of things about subscribing to a Blogger blog:
I don't yet know how to see if anyone has subscribed to my blog, although I think there's a way in Wordpress so there probably is in Blogger but I haven't found it yet.
I used the cunning ploy of subscribing to my own blog (using the Subscribe by Email box to the right of the page) with a different email address to see how often notifications of new posts come through, and what they look like.
It looks like notifications come through once a day and include all the posts published on that day. I like the fact that the whole text of the post is included in the body of the email; I was expecting only the first couple of lines and then to have to follow a link to the blog to read the whole thing. Thumbs up to Blogger for that! The screenshot below shows how the email looks...
(In an aside, I have just been shown by a 7 year old how to get ... on the iPad in one keystroke instead of having to press the full stop 3 whole times in a row: you change it to the number view, press and hold the full stop then slide your finger up when the ... shows to select it. No idea how he knows that but I'm impressed!)