Facebook reveals that they are having 4 million advertisers on its social network. Back in March, this year it was three million business  advertisers on its network. Within a shorter period of time, a huge number of advertisers were using Facebook as the medium to advertise their brand.

Facebook’s main current rival in the social advertising space, Twitter, claimed more than 130,000 advertisers in the fourth quarter of 2015. Facebook-owned Instagram announced last week that more than 500,000 brands buy its ads each month, up from 200,000-plus in February 2016.

In addition to Facebook’s advertiser base growing, the role of mobile for those advertisers is growing as well but in a different way than you might expect. You already know that more than four-fifths of Facebook’s advertising revenue is from ads shown on smartphones and tablets, but  did you know that 40 percent of Facebook’s active advertisers have created an ad using a smartphone or tablet? It’s true.

What might also surprise you, also in a different way, is how many of Facebook’s active advertisers are buying its video ads: more than 20 percent. That might surprise you, given how much attention Facebook and people outside of Facebook have put towards its video ads business, particularly since it rolled out autoplay video ads and in light of the recent hysteria over some erroneous video ad measurements.

But the stat doesn’t necessarily signal that Facebook’s video ad business is overblown. More than four million new video ads were created on Facebook in the past month. Instead, the fact that the majority of Facebook’s advertisers aren’t buying its video ads may have to do with the fact that more than 70 percent of those advertisers are outside of the US, and Facebook’s adding the most advertisers in southeast Asia, where people are most likely checking Facebook on poor cell signals that are served better by Facebook’s slideshow ads or text-and-photo ones than video spots.