So, the only thing left to see how far this thing goes is to see how you are going to monetize this?
I see you have plans to offer "Pro" features in the future... so does that mean limiting the current features?
The average Internet user spends 2.5 hours per day on email and most Screenleap users send links as their primary means of notifying viewers. We believe the Gmail browser extension makes it even more convenient to share your screen because we can auto-populate your emails or chat conversations with the share link so you don't have to copy-and-paste it yourself.
If Screenleap solves this then I'd be willing to give it a try.
Best practices would seem to be linking to an information page, not the direct download.