"We'll continue to experiment," Noto said.
More changes are coming, but don't freak out
Twitter has to appeal to people who use its site without signing in, but it hasn't forgotten about the diehards who built Twitter from scratch.
"Obviously Twitter will always be a real-time network," Noto said. "There are time periods when something incredibly relevant to you as a user could've occurred hours ago before you opened the app, and we will see opportunities like that to give you content that's relevant."
That means surfacing tweets to the top of a timeline where you can see them, or offering you tweets from people you don't follow if you pull to refresh and none of the people you follow have tweeted anything new. (After all, if you're not reading new stuff in your timeline, you won't see any ads to click. See?)
For new users, the fully populated, interest-based timeline is web-only for now, but Costolo said that effort will soon roll out to mobile. Costolo also has big plans for Fabric, the new SDK for iOS and Android developers that will help them build and monetize their apps--and puts Twitter front and center of those apps.
Ads for TweetDeck
Fabric's toolkit includes MoPub, Twitter's mobile app ad exchange that will help developers make money off their apps once they get the ball rolling. Costolo said there's an opportunity in "being part of the foundation of the entire mobile app landscape," and that opportunity includes extending the reach of Twitter's ad platform.
"We will think about and look for opportunities to provide our native advertising units in syndication, both to other Twitter-based properties like TweetDeck and across the entire mobile application ecosystem," Costolo said.
So don't be surprised when ads pop up in your favorite Twitter client or apps made with Fabric. It's all part of Twitter's rapidly unfolding plan to take over your phone without a phone of its own.
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