A lot of great products and services actually have two types of brands. They have a corporate brand that represents them as a whole. They also have secondary brands that live under the umbrella of the main brand. These are the ones people actually buy or utilize. An example that comes to mind is the Black and Decker tools company in Maryland.
A Family of Brands
They use the same orange and black color scheme for both their consumer line and their industrial line which is called Dewalt. Even though the names are different, the mind associates the very broad color scheme with both products. This lets the customer know it is part of the corporate family. The customer buys the brand name but is reassured of some overall characteristics that they expect from any brand from this company.
The same principle works for medical groups. On the one hand they have their main logo for the entire group. Then the medical specialties and clinics could be sub-brands with some unique characteristics of their own. There would be some variation in the brand elements but the specialty brand would be presented alongside the main brand.
Sub-brands Allow Better Targeting
This is important because as medical markets become more and more competitive, the specialty departments will need more to stand out and differentiate themselves. Instead of just being the cardiovascular unit of a medical group, the unit could have a unique name and logo. If people see nothing unique or different about the specialty groups, it will be very hard to build perceived value in their mind.
Another benefit is you can focus advertising on specific business units. When there is only one brand it is very hard to reach the different segments of the community. The specific brand can be tailored to reach different demographics. This can help maximize ad budgets while reaching people more effectively.
Sub Brands Are More Flexible
The number of places where people get media has exploded. They see advertising on their cell phones, tablets, television, laptops, and desktops. On those devices there are thousands of websites, social media groups, videos, movies and documents. Targeting every group over the same medium is impractical today. Different medical specializations to market across different marketing channels. Smaller brands allow you to use the preferred media for the target groups.