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.