Digital marketing is defined by the use of numerous digital tactics and channels to connect with customers where they spend much of their time: online. From the website itself to a business's online branding assets -- digital advertising, email marketing, online brochures, and beyond -- there's a spectrum of tactics that fall under the umbrella of "digital marketing."
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Personal selling involves an oral presentation given by a salesperson who approaches an individual or a group of potential customers. Personal selling allows for two-way communication and relationship building that can aid both the buyer and the seller in their goals. Personal selling is most commonly seen in business-to-business marketing (e.g.: selling machinery to a factory, selling paper to a print shop), but it can also be found in business-to-consumer marketing (e.g.: selling cars at a dealership). 
Positioning concerns how to position a product in the minds of consumers and inform what attributes differentiate it from the competitor's products. A firm often performs this by producing a perceptual map, which denotes similar products produced in the same industry according to how consumers perceive their price and quality. From a product's placing on the map, a firm would tailor its marketing communications to meld with the product's perception among consumers and its position among competitors' offering. 
Now imagine you had that brochure on your website instead. You can measure exactly how many people viewed the page where it's hosted, and you can collect the contact details of those who download it by using forms. Not only can you measure how many people are engaging with your content, but you're also generating qualified leads when people download it.
Digital marketing activity is still growing across the world according to the headline global marketing index. A study published in September 2018, found that global outlays on digital marketing tactics are approaching $100 billion. Digital media continues to rapidly grow; while the marketing budgets are expanding, traditional media is declining (World Economics, 2015). Digital media helps brands reach consumers to engage with their product or service in a personalised way. Five areas, which are outlined as current industry practices that are often ineffective are prioritizing clicks, balancing search and display, understanding mobiles, targeting, viewability, brand safety and invalid traffic, and cross-platform measurement (Whiteside, 2016). Why these practices are ineffective and some ways around making these aspects effective are discussed surrounding the following points.
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