A website isn’t the only interface through which companies can interact with their customers and users. Thanks in some part to the success of companies that have used APIs to help build significant business value, a growing number of companies in both the B2C and B2B markets are building and launching their own APIs.

Most APIs, of course, aren’t going to achieve Facebook-like success, and companies often make fundamental mistakes when developing an API strategy.

So what are the keys to success when API-ifying your business? Here are seven of them. 

1. Know your consumers, and understand their needs

Before designing your API, it pays to know who will be consuming it and what their needs are. While this sounds obvious, it’s not too difficult to find APIs that are of limited use and/or are challenging to use because they were clearly not designed with the consumer in mind.

2. Make your business model transparent

In both the B2C and B2B, APIs can be powerful assets and direct and indirect drivers of revenue. But they can also be liabilities when the business model for your API is opaque or worse, not determined. Don’t invite the kind of criticisms that plague Twitter: make it clear what your intentions are on the business model front, up front, even if the details haven’t been completely ironed out.

3. Think twice about throttling and access limitations

While companies operating the most popular APIs, particularly in the B2C space, may have legitimate technical reasons for putting caps on usage, throttling and access limitations more generally should be implemented in a thoughtful manner. Arbitrary limits can quickly become problematic, and in many cases, they’ll be out-of-whack with real-world usage, making your API far less useful, and potentially unviable.

4. Get some REST

The number of APIs built on REST principles has grown significantly in the past several years, and many of the most popular APIs are RESTful. If you’ve ever had to integrate with a SOAP API, you can understand why.

While REST isn’t necessarily the end-all and be-all of API implementation, a decision not to offer a REST API is one that shouldn’t be taken lightly

5. Try to get it right the first time

While a good API will almost always evolve over time as a result of feedback, keeping consumers of your API happy typically requires that you don’t make too many changes too often. While companies like Facebook can get away with API chaos because of their popularity, the better approach for most companies is to be thoughtful at the API design phase and strive for a good V1.

6. Focus on making integration easy, not on ideological perfection

The success of your API boils down to a few factors. One of them: how easy it is for developers to integrate with it. When integrating your API becomes a nightmare, the value required to make integration worthwhile goes up significantly.

With this in mind, it’s worth considering that an API that’s easy to work with isn’t necessarily going to be one that is perfect from a pure technology standpoint. Many RESTful APIs, for instance, are criticized by purists as not being RESTful enough, but at the end of the day, if forced to choose between building something loved by the people you serve or building something that pleases the purists, the right decision should be apparent.

7. Document, document, document

The best APIs are almost always well-documented APIs.

While there’s no single template for API documentation, the best documentation will include, at a minimum, clear, concise descriptions of API endpoints and what they do, and request and response examples. Many developer portals also allow developers to issue requests and receive responses, which can be a big help.