It's about your web strategy, not just a web site.
A web strategy is so much more than a web site, in the same way a marketing strategy is more than the individual marketing components. A web strategy is about how you use web based technologies for your organisation / business.
Technology itself cannot resolve fundamental issues. Your business needs to utilise technology in smart and effective / efficient ways to help it connect with and provide for the users (or community) that are likely to or already have an interest in your offerings.
Many web sites are seen as the strategy, yet fail to provide any meaningful results for the business investment. In essence, most are little more than modern brochureware sites that may work well and look nice, but fail to be anything other than a small part of the organisation's offerings.
A web strategy seeks to identify all the opportunities that are suitable for effective web technology, which includes understanding the audience, knowing the capacity and resources of the organisation, being across the broadest possible coverage of technological issues and creating a vision and roadmap of how to find the sweet spot between them all.
Jeremiah Owyang expresses it as finding the web strategy balance between the three spheres of web strategy: community, business and technology.
web strat-e-gy [strat-i-jee] how to use web technology for your organisation / business
Many development / design companies can produce quality work but it stands in isolation to the overall business goals. A strategy will incorporate how you wish or need to communicate to the different groups, what your business objectives are and what technological solutions exist to meet those objectives. How will the technologies be integrated to the business, what human resources will be required, what is the corporate communication style, how would more direct tools work within the company structure? Of course budget matters, as well as how to integrate, train and measure success or failure.
Not all roads are paved with gold, and utilising the many technologies available and / or opening the door for direct communication between your company and your customers, requires a willingness to have a few failures, or issues, and to learn how best to handle these types of issues.