Why do you (usually) need to enter your e-mail adress when commenting a blog post? I guess it's for some kind of spam-protection but if the system doesn't need it - is it ok to skip that input field or could the be another reason to keep it?
One of the main advantages for requiring the user to enter in their email address when commenting is actually for the site administrator. There may be instances where your comment prompts a response not suited to, or too large for the comments section, and as such they will contact you directly.
It also acts as an extra barrier (although not a very good one) against spam and troll commenters. The mere fact that the user has to complete an extra field and make up an email address just to write "first" on a post, will turn that user away in many cases.
My web comic doesn't have login accounts -- it's more secure for my site as a one-person operation and it reduces barriers to getting people to comment. Asking for an email address serves two purposes:
- It allows me to pull up the associated Gravatar with that account, giving the user some degree of identity.
- Because the email address is not shared on the live website, this combined with the gravatar functions as a de facto password -- People could attempt to impersonate another user, but without knowing that user's email address (to produce the right gravatar), nobody'll believe them and it won't work. Yes, this gets defeated as more people know that person's email address, but it prevents at least passive spammers and vandals from doing so, which is enough for my purposes.
Reason to include an email address:
- The blog owner might receive the comment as e-mail, by adding the commenter his/her email address, the owner can immediately respond by sending a reply email.
- The commenter might receive an email notification after posting comment
If both cases do not apply, leaving it out might simplify the commenting experience.