By Janette Speyer, Web Success Team –I am often asked to include an interpretation of Twitter engagement in our monthly reports to our clients. Most of the time it is hard for people to gauge the return on investment of a simple feed. Our projects at the agency include working with bloggers and brand ambassadors at an event, trade show or for a brand launch. When we complete a campaign, we examine interactions, engagement and impressions. This is how we determine the success of a product. T...