Everywhere. Every department, every campaign and every project should be employing the use of analytics. For example:
Analytics in SEO: a data-driven approach to SEO will improve the relevancy and quality of content.
Analytics in Sales: growth hinges on understanding trends and consumer behaviour. By using Analytics you can increase customer engagement, better understand their needs, better understand who is most likely to make a purchase and increase lead generation and conversion.
Analytics in Social Media: Analytics will allow you to identify customer interests, preferences and buying patterns. Furthermore, Analytics can be used to predict future trends before they even start. Marketing strategies can then be optimized for these interests, preferences, patterns, and trends.