Building an ecommerce team: Start with generalists or specialists?

How should you go about building a new ecommerce team for an existing business?

With extra capacity required across the business in marketing, merchandising and product lifecycle management, development projects, and business processes, how do you decide on the best approach for building a lean but effective team?

Do you start with a generalist who can do a bit of all, or a specialist to take over one aspect more completely?