Global Digital Marketing Courses Market By Type (Search Engine Optimization (SEO) , Search Engine Marketing (SEM) , Social Media Marketing (SMM) , Email Marketing , Inbound Marketing , Growth Hacking , Web Analytics , and Mobile Marketing), By Application (Smart phones , Laptops , and PCs), By Region, and Key Companies - Industry Segment Outlook, Market Assessment, Competition Scenario, Trends and Forecast 2020-2029