From a model-building perspective, the 4 Ps has attracted a number of criticisms. Well-designed models should exhibit clearly defined categories that are mutually exclusive, with no overlap. Yet, the 4 Ps model has extensive overlapping problems. Several authors stress the hybrid nature of the fourth P, mentioning the presence of two important dimensions, "communication" (general and informative communications such as public relations and corporate communications) and "promotion" (persuasive communications such as advertising and direct selling). Certain marketing activities, such as personal selling, may be classified as either promotion or as part of the place (i.e., distribution) element. Some pricing tactics, such as promotional pricing, can be classified as price variables or promotional variables and, therefore, also exhibit some overlap. What is Digital Marketing?
This refers to how the product gets to the customer; the distribution channels and intermediaries such as wholesalers and retailers who enable customers to access products or services in a convenient manner. This third P has also sometimes been called Place or Placement, referring to the channel by which a product or service is sold (e.g. online vs. retail), which geographic region or industry, to which segment (young adults, families, business people), etc. also referring to how the environment in which the product is sold in can affect sales.  5 Digital Marketing Skills to Master for 2020 & Beyond