Campaign Monitor’s blog has a post about their new office space, and in it they write about several reasons why private offices are necessary for programmers, including this quote from Paul Graham:

“After software, the most important tool to a hacker is probably his office. Big companies think the function of office space is to express rank. But hackers use their offices for more than that: they use their office as a place to think in. And if you’re a technology company, their thoughts are your product. So making hackers work in a noisy, distracting environment is like having a paint factory where the air is full of soot.”