I think the mild frustration Andrew feels when he gets asked this question is because it’s really hard to pinpoint success.

Granted that doesn’t keep designers, VCs, or product people from undertaking the task of figuring out why something was successful. It’s our instinct to form narratives.

I read recently about the concept of emergent properties, which has me thinking differently about why things “take off” or work — especially in cases where it doesn’t seem like there was anything novel.

Emergence observes that a property can arise from substances when they’re combined, that didn’t exist independently in each substance. For example, the property of saltiness arises when sodium and chloride are combined, but that property doesn’t exist independently in either sodium or chloride.

I feel that way about the success of Slack. The design, name, onboarding, ease of use, timing, initial launch, chat-focus, and tons of factors came together at once to yield the property of success. To say that it was the design or marketing effort or the playful feel is to discredit the phrase the whole is greater than the sum of it’s parts, which Andrew, too, concludes.