I'm not a huge user of Buffer, but I really like them because they've given us great insight into running a startup that's not a smash-hit-media-darling. VCs weren't knocking down their doors with truckloads of cold cash, they weren't beating journalists off their backs, etc, you get my point. They've had to stick to business fundamentals from day 1, methodically approaching issues like profitability, marketing, business development, growth, with only $500k of investment. They've been up and running for a few years now with a team of ~17 who're being paid competitive salaries. They've no doubt learned a lot and have been open about it. And this is just another example of their strategic biz dev, marketing and transparency they've become pretty masterful at.
I should add that this is also a great move by Baremetrics, who are likely to gain much more out of this.