One million users signed into Twitter's new live streaming app Periscope in the first 10 days after its launch, according to TechCrunch. That's a fast clip for a new social network, but can its momentum continue?
The challenge facing Periscope isn't user interest or support from its parent, Twitter.
It may come down to usage and speed.
If a user is on a data connection, streaming video can rack up data costs on wireless phone bills.
The bandwidth risk is on the consumer side, says one tech expert.
"A few hours of streaming a week and they'll easily blow through their mobile data plan limits. The sticker shock could end up curbing usage in a blink of an eye," said Lou Basenese, founder of Disruptive Research.
The app is still not yet available to Android users.
Disclosure: CNBC's parent company, Comcast, is an investor in Meerkat, a rival of Periscope.