[dylan604]

TikTok was mobile device centric, and the people that glommed onto it quickest were young mobile users. StumbleUpon was just a website that the "olds" used. Maybe I'm wrong, but did SU have a mobile app? If so, they did a very bad job of getting it into the hands of those that TikTok did.

[dfabulich]

StumbleVideo was exactly like TikTok, including focusing on mobile. The only material difference is that StumbleVideo's videos were landscape instead of portrait, and they had a "Stumble" button instead of swiping.

(Maybe it's the swiping gesture? Maybe the gesture is more comfortable in portrait?? But it's hard to see why that would make or break a video app like this…)

[wyre]

I used SumbleUpon but not their video service, but some differentiating factors is TikTok specializes specifically short form video content in an environment where creators are rewarded and incentivized to make addictive content.