What does a "Digital Marketing" agency do?

In very simple words Marketing agencies, also called marketing firms or marketing companies, help clients implement and manage marketing strategies to achieve their business goals. Getting your website to the top of the search engine results is just one half of the battle. Keeping it there is continuous process and a challenge. 
Digital marketing agencies employ strategies like Search Engine Optimization, Search Engine Marketing, Social Media Marketing, Email Marketing, Content Marketing, and Mobile Marketing to ensure that your business website and your brands are always visible to the online customer. Now that you know what all activities are involved in digital marketing, you can see why the scope of the marketing cannot be managed by a single person. This is the reason that digital marketing agencies are there to help companies.
What Digital Marketing Can Do For Your Businesses?
Many people thought that anything can be done on the internet, so they themselves can manage the marketing also. Maybe write some blogs, create a Facebook page, sharing on social media– but it is hardly a one-time activity. If you spent all the time in marketing then who will take care of your business? Continuous work is needed and different expertise is required for successful marketing. That’s we need to hire digital marketing agencies. Let’s understand what they can do to keep up your business in the market.
there are many elements to digital marketing right from website design, to app development, to content writing, to SEO. A digital marketing agency anywhere offers comprehensive services and is cost effective because you pay much less for a variety of personnel than what you would be paying if you hired all of them full time. Marketing agencies execute and manage marketing campaigns for clients. 
If you are worried that a digital marketing company won’t prioritize your brand then don’t worry. For an agency every client is important and they have dedicated teams to ensure that all clients get equal attention. A great digital marketing agency is made up of a team of diverse talents and expertise. They should be a multi-disciplined team, with unique experts in their respective fields like design, development, SEO, content strategy, social media, brand development, etc.