I don't really understand the privacy part. You feel compelled to say it's anonymous, and then torture yourself over it.<p>I'd be  perfectly fine with telling users "This survey will be linked to your account.", except that it sounds weird/unnecessary.<p>Paying customers don't generally expect/desire anonymity. Most probably <i>want</i> you to know <i>their</i> opinion.<p>A survey like this is little more than a predefined conversation between you and your customers. You're not anonymous in your regular communication (email/phone), so why would you be for the survey?