If the vision for the blog is to sell products (etsy) or write a book, or build a following, then you need a way to reach out to your subscribers on a personal level and connect with them. Email is still one of the best ways to reach people online. Some bloggers send out newsletters.
And the best way to build an list is through give aways.
I have benefited from giveaways but I was going to comment anyway. If I did a giveaway I think I'd try to figure out who the regular viewers are and do a draw from 'the regulars'.
I do not want to build a list but I am certainly willing to connect through emails. I do have a few blog friends with whom I have connected that has gone beyond blog comments. And this has been the best that blogging has offered me.