Two years ago the world’s largest companies were experimenting with social media. Now you can’t get them to shut up—and that’s probably a good thing for the companies because people are talking about them online a lot.

Businesses comprising the Global Fortune 100 are mentioned 10.4 million times a month on social media, the vast majority of which occurs on Twitter, according to Burson-Marsteller’s third-annual Social Media Check-Up.

Perhaps that explains why Twitter is the most popular social network among these companies, with 82 percent having a Twitter account. And the vast majority aren’t broadcasting messages—they’re engaging with consumers: 79 percent of corporate accounts attempt to engage on Twitter with retweets and @ mentions.

The Global Fortune 100 firms also follow more people on Twitter than they were in 2010. On average, a Twitter feed belonging to one of these companies follows 2,062 people—a 182 percent jump from two years ago. Meanwhile, the average number of people following the accounts has tripled in the last year to 14,709.

YouTube, which is the next most-popular platform, saw the sharpest increase in use among the Global Fortune 100. A full 79 percent have branded YouTube channels, marking a 39 percent spike from 2010. These YouTube channels average more than 2 million views and about 1,600 subscribers.

Nearly three-quarters of the companies have Facebook pages. The average number of “likes” per page is 152,646. And 93 percent of the Facebook pages are updated weekly, up from 59 percent in 2010. Better yet, 70 percent of corporate Facebook pages are responding to comments on their walls and timelines.

Meanwhile, 48 percent of the Global Fortune 100 have a Google+ presence, while 25 percent are active on Pinterest.

Overall, the percentage of Global 100 firms using at least one social network is 87 percent, a 10 percent increase from 2010.

Among a handful of emerging trends noted by Burson-Marsteller is the increase in companies launching multiple accounts for each social media platform. Ford and Wells Fargo, for example, have Twitter accounts for different products, services, and more.

Another trend is content creation. Former Burson-Marsteller CEO Mark Penn said in a press release that companies’ social media use has evolved since 2010, from broadcasting to engagement to content creation.

“Companies are now integrating more original multimedia content to share with followers on Twitter, Facebook and YouTube,” he remarked.

Here is the full PowerPoint presentation on the Social Media Check-Up, which includes data from Visible Technologies: