One-sided point of view. Inaccuracy in response to a survey due to a sample not corresponding with the universe. A bias can also be introduced by an interviewer who allows his own views to influence answers.
The Mathematics of Direct Sales and Performance Marketing Profitability: How to Make One-Shot and Subscription-Based Products and Services Viable
Before you even begin to think about the detailed techniques of performance marketing and selling your product or service directly – the market, the design of the material, the method of order fulfillment – you …