Twitter's quarterly revenue grew at its slowest rate since going public in 2013. Revenue inched up just 1 percent, and ad revenue fell amid growing competition. Analysts say advertisers are shifting to Facebook. CEO Jack Dorsey was upbeat about the growth of its audience. Twitter's user growth got a boost from President Donald Trump who actively uses it to air his views, thereby growing his follower base. But Wedbush Securities analyst Michael Pachter said, "The shocking part is that the Trump effect was zero. Their growth actually slowed during the quarter." Twitter shares, up less than 2 percent this year, plummeted at the start of trading.