+1 Streak (http://www.streak.com)

Streak is great! We were looking for a lightweight CRM that our team would actually use. Streak does everything we need it to and it does not require our team to dramatically change their work flow.

Everything is right inside Gmail and so for us, at this stage, Streak is perfect. Plus, tracking feature is cool. Easy way to see if an email has been read.

Rapportive (https://rapportive.com) is really what makes our direct sales possible. And, Streak plays nice with Rapportive.