Since the days when the snake-oil salesman would roll into town with a well-placed accomplice in the crowd to support bogus medicinal claims during his sales pitch, promotions professionals have struggled with issues of transparency and full disclosure. The Web has replaced the stage outside the covered wagon as the venue of choice, but the issues are still very relevant as word-of-mouth marketing and testimonials remain effective promotional strategies.

So, when is the line between creative publicity tactics and ...