I found myself using a hashtag in an email recently. First time. But I liked doing it. I wrote a few lines of email, and then I put down the hashtag at the end which captured the entire email in one word. I felt good doing it.
Isn't that the point? But on Twitter the hashtag lets you reach out to other like-minded people. Over email that is not the case. So I think I just invented a new use of the hashtag.
There is so much room for innovation within the inbox. The inbox is wild territory.
Come to think of it, emails should also have labels/tags like blog posts do. I think.