[chaz]

I won't argue that it cost them precisely $0. But the marginal cost of this tweet was pretty close to free.

Let's be realistic -- there's no way they had 15 FTEs fully dedicated to social media. Instead, it's 15 people from Customer Service, and/or Marketing, who are already employed at the company. When the company spends $4mm on an ad, it likely turns into a Super Bowl party at the office, with free pizza and beer in the biggest conference room in the building. The 15 get a bit of training and access to Hootsuite, which is what @Oreo is using, and asked to stand by with their notebooks if things got crazy.

At a previous job, when we had a big marketing event like this, it was all hands on deck, and everyone, no matter what your normal job function, was to answer phones. Our 40-person Customer Service team was actually 2 Customer Service people, augmented by the CEO, all VPs, marketers, sales, etc.