What do you say to create more interest and get an add-on sale from an existing client?  Ask powerful questions that tell you where the customer is focused and learn more about how their business works.

Example questions to ask:

Is this a busy time of year for you? (if yes, ask about it, and if no, ask whether business is just constant throughout the year)

What are you working on? (for some reason, this question tends to disarm people - they don't know if you are talking about business or personal, and tends to be a great conversation starter)

What are the goals for the company this year? (shows whether your contact is clued into the business plan, vision, and mission)

Are there any challenges you're facing that I might be able to help you with? (listen and see what it is they are stuck on or troubled with)

There are many more of these questions - what ones work for you?