I think marketing communications plays a significant role in the success of a company's overall marketing strategy because of the breadth of coverage available to a company that utilizes an effective marketing communications strategy. Marketing communications encompasses a broad set of activities under the overall business marketing umbrella. It involves offline and on-line marketing - including the use of social networks.
It also includes direct selling, sales promotions, advertising, public relations, promotional events, personal selling on the part of sales personnel, as well as branding. Furthermore, marketing communications involves taking part in trade shows and conferences to get the word out about products and services.
Therefore, marketing communications is significant in scope. Combined, all, or most of the above elements used, are a powerful force for a business enterprise in getting their name known, their products known, and their reputation established.
A company's overall marketing strategy will be more effective when their marketing communications initiatives are a cohesive lot. A business must get out a consistent message about their company, no matter how many and what types of marketing communications avenues they employ. The goal is to get the same message out about what they offer.
The worst thing a company can do is transmit conflicting messages. They may say one thing on Facebook and Twitter, another thing in their print advertising, all the while having their salespeople trumpet another message. This is confusing to consumers. An effective marketing communications strategy stays on the same message, despite the diverse channels the message is marketed through each day.
Marketing is the arm of the business that is in charge of "messaging" to the consumers (and the marketplace) the image or brand of the company and its products and services. Most people receive messaging about many companies--including those they have never used via the Internet, TV, radio, etc. So, individuals make decisions and first impressions from the messaging they see about products and services. For many people, this is all they receive as they may never use a particular product or service. This brand "messaging" is the essence of marketing communication. Getting "the word out" about your product/brand is the way your company makes impressions on people. As a company, you have a very specific image that you want to communicate to the world and you must control all communications to make sure they support this message. For instance, in the fast food industry, there are many urban legends and myths. For instance, one popular one is that KFC has places where there are headless, limbless chickens that are raised for this product. Although this is not true, it is important for KFC to constantly remind people that its products are "down home," and fresh from real chickens.