Slack and Basecamp are fundamentally different tools. I use both on a daily basis and they are not interchangeable. I also can't remember a freemium model on basecamp either - it's been a paid service ever since. They did change their pricing structure when moving to BC3, so now it's mostly flat and not tiered by team size and resource consumption.

Read the parents. Twitter and other social media are fundamentally different; most product businesses are going to give a different offering. The guy is saying that competition in the space will steal eat your lunch for you if you don't take investor money, and that's just not true.

I wasn't aware about the details with the pricing of Basecamp. I just knew it changed recently and that it wasn't freemium. The point I was making with that still stands.