There’s no single list of ingredients for creating a successful website. The design and user experience of any company website should be a unique, carefully considered blend of usability, brand identity and conversion goals. Having said that, there are common features that achieve a certain clarity of purpose, and, by extension, success. Here are five of them.

Professional Design
Your site may rank in Google's top five, but if it looks like your nephew designed it, you’re going to run into problems. Spending time engaging a professional designer with an appreciation of usability issues will pay dividends. It can help identify conversion goals and appropriate callouts, it can reinforce or establish your brand proposition, and it will bring a level of polish to your site that most people have come to expect.

Positioning Statement
This is the opportunity for your homepage to clearly explain why it exists. It is not an expression of a brand value (like a tagline), but a simple statement of fact.

Example of positioning statement: “We are a multidisciplinary web design and development agency based in Boston/focused on usability/dedicated to client service”

Example of a tagline: “Building a better web since 1998”

Positioning statements are important because they provide first-time site visitors a clear indication of the type of site they're looking at. And this is about clarity so, please... leave out the buzzwords.

Callouts and Calls-to-Action
Speaking of clarity, let’s define callouts as elements on the page (not those contained within navigation), that inform users of deeper site content that may be interesting, relevant, or otherwise important. These may appear on a homepage or on deeper pages of the site, usually within a sidebar. A call to action is a more general term, inviting a user to a direct course-of-action; online this most often takes the form of a link, but the concept can map to offline communications as well. In fact, you’ve probably seen dozens today already: every time you see a phone number or a website address, you're seeing a call to action. In marketing terms, calls-to-action provide the opportunity to transform a passive recipient into an active investigator.

Of course on the web, callouts and calls-to-action are used more or less interchangeably. Regardless of how they work, they provide the opportunity for specific conversion goals to be identified and tracked. And that makes them a powerful tool for any website.

Coherent Navigation
If a website is like a car, then the navigation is the steering wheel. It is the primary means by which users move from one site page to another — a naviagation that's difficult to use or understand can very easily lead to frustration.

Navigation needs to make conceptual sense and have visual consistency across pages. By conceptual sense, I am actually talking about the sitemap: how site information is organized, grouped, and interrelated. From a design and usability perspective, navigation needs to be easy on the eyes and easy to use. It’s entirely possible that there are better navigation schemes out there than the current conventions; but in the meantime, it’s best to make it as usable and consistent as possible, especially for business applications.

Telephone Number on the Homepage
It seems like a small thing, but including a telephone number prominently on a site can confer numerous benefits. On the usability side, it means that customers and clients don’t need to search through the site to find out how to reach you. Ensuring that the number is text (as opposed to an image) is likewise important, since many users are accustomed to copying and pasting from one application to another. Forcing a user to either write down a number longhand, or type it into another application or device, forces an unnecessary step.

Whether this number should have pride of place or be relegated to the footer is, of course, a question that different businesses will answer differently. The staff's call volume, the number of service actions that can be handled online, and the nature and business model of the company may all influence the prominence of a telephone number on the page.