i am looking for a way to display a button on categories/authors fro guest to subscribe to updates. The site owner DOES NOT want the guest to have to go through the process of registering on the site to create a joomla/k2 user. He only wants the guest to be have to click a subscribe button, enter their email address and then the guest receive updates.

I found a few extensions that do this but only AFTER the guest has registered on the site and created a joomla/k2 user.

Anyone dealt with this already?

If the user who chooses to enter their email is not registered in the site how are you suppose to keep track on everything?
Still, the email has to be stored somewhere.

thats a good question BUT its being done. Take a look at this page: www.examiner.com/article/leggett-leads-north-to-title-game-with-287-yards-27-21-win-over-mceachern

in the author info below the article is a subscribe option that only needs your email

This is more like a newsletter plugin. Still the email probably is stored somewhere in the backend.

Maybe you should search for something like that rather than other subscription mechanisms.

thank you for the quick replies and advice. I found a newsletter i am trying (www.acyba.com/) but will have to see if this works with K2 items. This does look like what the site owner is looking for though. Anyone else advise on on k2 compatible newsletters?

Thank you again for the quick reply and guidance. The newsletter solution acymailing has a number of plugins including K2 user/content. It may not be free or cheap but it does just what the site owner request!