While Twitter Inc. has 284 million monthly active users, it isn’t growing nearly as quickly as many other social networks. Part of the problem, Twitter suggests, is that far more consumers—as many as 500 million—view Twitter streams on other sites and apps, rather than on the social network. And those consumers don’t have to log into the social network.

Twitter today took its first step to making money from people viewing tweets off of its platform by serving marketers’ promoted tweets—its ad unit that lets an advertiser pay to ensure a particular number of consumers see its message—to two Yahoo Inc.-owned sites and apps, news reader application Flipboard and Yahoo Japan. Both host sections on their sites that feature Twitter streams.

Twitter, which syndicates tweet streams to thousands of sites and apps, says it plans to syndicate the ads to more sites and apps.

“For the thousands of brands already advertising on Twitter, these new partnerships open a significant opportunity to extend the reach of their message to a larger audience,” writes Ameet Ranadive, Twitter’s senior director, product, in a blog post.

Twitter will let advertisers target audiences off its platform in the same ways they do on Twitter. That means an advertiser can run a promoted tweet campaign with specific creative content and targeting on Twitter and simultaneously run a slightly different campaign off of Twitter with different content and targeting in the Flipboard app. Because Flipboard already features unpaid tweets in its app, the promoted tweet will have the same look and feel that is native to the platform.

The move to expand its ads’ reach, should help Twitter grow, says Lou Kerner, a social media analyst and investor at The Social Internet Fund. “If Twitter can extend the reach of marketers’ ads by having those ads seen on more sites, that’s helpful to the overall Twitter ecosystem,” he says.

Twitter says the move is the first of several steps to generate revenue from consumers who view tweets off of its platform.