Avoid long domain names. They may be good for your SEO but not for your visitors. They will not easily remember your site. Moreover, there are also other SEO methods that you can use without using domain names that are too long.
I hate it when I see long domain names, containing four words or more. I think a domain name should be short and easy to remember. You wouldn't expect internet users to remember a five word long domain name, right?
No, five words would probably be to hard to remember. But, that's if we're talking about branding. If you're just hoping to show up in serps, a long domain might be okay.
For instance "What To Do in Boston" would be a five word domain. However, I would go ahead and say its fairly valuable.
I hate it when I see long domain names, containing four words or more. I think a domain name should be short and easy to remember. You wouldn't expect internet users to remember a five word long domain name, right?