During the weekend when TikTok was briefly offline, Whatnot -- a platform that lets online brands and merchants sell products via livestreams on its app and website -- saw its user numbers surge.

"It was our biggest weekend for new sellers -- both in terms of news sign-ups and also sellers who went live for the first time," said Armand Wilson, vp of categories and expansion at Whatnot. "Over that Saturday, Sunday, Monday, we saw a huge spike -- and we continued to see those numbers since then."

It points to the uncertainty permeating the social media landscape right now. While TikTok is back up and running, it's unclear what its future is in the U.S. And more brands are testing out other startup social commerce platforms.

On this week's Modern Retail Podcast, Wilson spoke about the rise of Whatnot as well as what he's witnessed during the last six months when TikTok's future became unclear. "Particularly [at] the tail end of last year, we are hitting this kind of inflection point," he said.

Still, Wilson was clear that even though TikTok, a major competitor, has been constantly in the news, he and his team tried to remain focused. "We really, truly tried to not spend a ton of time thinking about competition," he said.

At the same time, the constant changes likely had an impact on overall adoption of social commerce, which still remains nascent in the U.S. "We've definitely seen a big growth in live shopping as a whole," he said. "And I'm sure some of that can be attributed to some of our competitors pushing and getting more vocal."