If you’re a small to medium sized business running a whole set of websites, I’d wager that you probably wish you weren’t. The overhead of keeping them all updated behind the scenes, monitoring so many sets of visitor analytics and wondering if it was OK to duplicate content is enough to keep anyone awake at night. Then there’s the dilution of the external links, the possible confusion of multiple domains being at the same physical address, or the difficulty of explaining to customers that the businesses are linked – the list goes on.
Of course, there are many legitimate reasons why you might want or need separate domains for different business ventures (most obviously that they’re unrelated). But if not, the default should be to minimise the number of websites you run, with just one, if possible, being the easiest, cheapest and most effective of all. Don’t be tempted to launch unnecessary sites by spurious SEO-related claims such as being able to get lots of positions in the search engine results, or being able to include keywords in the domain name.
There’s always an exception to the rule, of course, and using throwaway domain names for specific campaigns is one of these. Getting people from print to web is a problem that’s never been solved, but a specific domain that people can type in for a particular offer is a smart idea. However, there’s no reason why this can’t just be redirected to a page on the main website.