“What we’re seeing is that people are using Twitter to instantly connect with things that are most meaningful for them,” Bain said, who cites examples like people Tweeting about NASA’s last space shuttle flight, Retweeting a charity link to benefit victims of the earthquake in Japan, or Shaq announcing his retirement from basketball via Tweet. Apparently, it was that ubiquity that spurred Apple to integrate the social network across iOS5, which hits devices this fall.

And despite some questions — including some raised by Fortune — over the last year regarding its monetization efforts, Bain provided some updated marketing and user engagement numbers indicating there’s real potential for the social network to turn a substantial profit and take advantage of what he views as a relative lack of engagement in digital advertising.

Compare that with Twitter, which Bain says is rife with potential. Currently, 20%-40% of all users follow some sort of brand, and for all new users, one of their first 10 “Follows,” or accounts they follow, is a brand.

“It’s usually people they know, people they wish they knew, and then brands they’re familiar with,” he says.

When it comes to Twitter advertising, Bain says Twitter 80% of Twitter engagement consists of people clicking on a Tweet, while the remaining 20% is a Retweet or a Tweet. He thinks those are powerful signals, particularly if a user Retweets an ad: in doing so, they’ve transformed it from advertising to content endorsement. Case in point: two of the top 5 Tweets of all time are actually ads from McDonald’s (MCD) and Disney (DIS) — the others include Stephen Colbert’s Tweet about the BP (BP) oil spill and Barack Obama’s victory Tweet, “Yes we did.” And when Volkswagen decided to unveil the new Beetle exclusively on Twitter, the auto maker saw a 52% engagement rate, which Bain says may have been the first time in digital advertising that “you were a minority if you didn’t click the ad.”

That’s probably why, despite the company’s experiments which have occasionally resulted in failed experiments like its Early Bird promotions, marketers remain keenly interested. When Twitter rolled out Promoted Tweets roughly a year ago, there were six marketers; now there are 600. And moving forward, the company plans to roll out a self-service dashboard for marketers later this year that will enable them to target users and study how users are interacting (or not) with their efforts.