Lets say that you run a business that has several aspects to it. Perhaps you have a hotel with a separate restaurant or a casino with a spa and a golf course. You should develop separate brands and websites for those aspects of your business. Here are three reasons why:
1 - Improved Demographic Targeting - By separating the marketing for the brands your message can be more relevant to each customer base. For example if you have a separate social media channel for your golf course you can post content that golfers find interesting or target them with a promotion specifically for the golf course. You will build smaller but more specialized audiences and be better able to communicate with them more effectively
2 - SEO - With multiple web properties and their social media channels you are taking up more room on the internet. As your properties mature your visibility will drastically increase. Instead of showing up once in the search results you might be able to appear multiple times. You also have the flexibility to optimize differently for each of your niches thus rank highly for many more search terms if done by an experienced SEO.
3 - Improved Branding - By separating your services into their own brands consumers will be more aware of the spectrum of services you offer. The brands will be free to stand on their own and develop their own message. Even if there is not the budget for separate print marketing, social media can be leveraged at a fraction of the cost. Multiple websites are NOT for every company though. More on that in the future...