Imagine if you knew exactly when new business leads opened your email, what link they clicked on, and what device they opened it with. No, we're not talking about those annoying email delivery and read receipt confirmations. Instead, we're talking about a powerful app that is non-intrusive, easy-to-use, discreet, and one your customers won't even notice. Does such an app exist? It does, and it's called Hubspot Sales from Hubspot.com and its free.