Why did Joel buy back equity from his investors?
After raising two rounds of funding in the start of the journey for Buffer, he searched from investors that were as excited about the products and company's growth potential. Once the company was profitable, it was during the negotiations where they shared that they may not ever want to sell the company or go public, so they might want to give a return and buy their dividends.
Once this was shared, the lead investor suggested putting that information into the terms of investment because it that allowed them to get a set down return whenever Joel and his company bought back the shares. They were able to use this option as a backup and as a way to still have control over the destiny of the company.