[vkjv]

I echo this sentiment. Full-stack means that you can support all aspects of the stack, and here's the key, that need to be supported by a dedicated person.

For example, most people "out source" their network / system administration to a company like Rackspace or Amazon. I would still consider someone utilizing their services to deliver a product "full-stack".

[IgorPartola]

Right. I find this term most useful in terms of building a team. Do you need to hire one person or two to get the job done?

Now, that's not to detract in any way from people who specialize. A good front-end developer with design skills can often get the job done faster and simpler. A good backend specialist can get performance under control sooner.