Instagram engineer Ryan Gomba sits on top of the Facebook sign at Facebook's… (Josh Edelson/AFP/Getty…)
SAN FRANCISCO -- Twitter Chief Executive Dick Costolo said this week that he's not worried about Facebook's launch of video on Instagram, which competes directly with his company's product Vine.
"Other people can replicate that or take pieces of it if that's what they want to do," Costolo said.
But one week into the battle for video between the two powerful social networks and Instagram appears to have -- at least temporarily -- dampened enthusiasm for Vine.
The sharing of Vine videos plunged on June 20, the day Instagram unveiled video for the first time, says Matt McGee, editor-in-chief of SearchEngineLand.com.
PHOTOS: The 10 biggest tech gadget fails
According to Topsy, there were almost 2.5 million Vine links shared on June 19. The next day only about 1.5 million were shared.
That decline continued over the last week. On Wednesday, there were fewer than 900,000 Vine links shared on Twitter, a 70% drop from the nearly 3 million links shared on June 15, McGee noted.
Vine is a video-sharing app that lets anyone create six-second videos that run on an endless loop. Instagram now lets users record up to 15 seconds of video, enhance it with 13 filters and post it immediately to Instagram or Facebook.
Instagram video is also gaining traction with major brands such as Ford, Disney, Burberry and Starbucks, Mashable reports. Fourteen of Interbrand's top 100 global brands have posed videos on Instagram, according to data provided to the blog by Simply Measured. Seven of those brands posted videos on Vine this week.
Tech giants battle over video
Facebook to challenge Twitter's Vine with Instagram video
Is Facebook worth it? Film execs confide they may cut movie ads