Thanks Tanya. I think its important to acknowledge that having a commercial interest in a customer and being trusted are not mutually exclusive. All the best sales people build trust in order to sell effectively and customers are well aware that everyone they deal with from a vendor (especially a resource given to them for free) has a commercial interest. As a CS professional what I've seen work best is to be upfront and let the customer know that of course you have a commercial interest but that you understand you will not have the right to discuss doing more business with them unless you work hard to show them real value from their purchase and showing them value is what you will be committing to delivering for them. In my experience, this level of openness builds a lot of trust and credibility with customers.