Streak! Email Monitoring for Gmail Users

I use Outlook for my primary VoiceMatters business but also have in-house Gmail accounts for a couple of clients. Gmail is great for its mobility. Outlook is great because, as business sometimes requires, I want to see that the recipient actually received the email I sent. I'm one step closer to having it all (at least in the context of email - I know, how sad) with the discovery of Streak.

Streak is a chrome extension that allows Gmail users to see when a recipient has opened an email that you have sent. There are many more uses for Streak, which I'll share via this article from Mashable. Me? I'm pretty easy to please and have only used the "email read" function. So far.

Do you use Streak? If you do, or if you're going to try, tell me how you like it!