Twitter announced on Tuesday that advertisers now have access to expanded options when it comes to serving up Promoted Tweets to smartphone users.

Twitter began testing Promoted Products on mobile devices three weeks ago.

They started with a small group of advertisers, and began serving up ads on their Twitter for iPhone and Twitter for Android apps for the first time. A small number of users may have noticed ads appearing in their timelines while they tweeted from their phones.

And now, even more of us will be seeing mobile ads on Twitter.

Today’s announcement came with two main pieces of news that should be of interests to both advertisers and smartphone Twitter users:

• Advertisers will now be able to target ads specifically to iOS and Android users
• Promoted Tweets will be now be visible in the timelines of users who share similar interests with an advertiser’s existing followers

Twitter is doing its best to ensure that Promoted Products appear the same across all of its web and mobile properties. Just like on Twitter.com, when smartphone users see a Promoted Tweet in their timeline, they will only see it once and it will scroll just like a regular tweet.

The ability for advertisers to target mobile-only Twitter users is an especially interesting piece of news. It means that timely tweets, like one from American Express about Jay-Z’s performance at SXSW or one about a deal on Android apps, will be especially effective.

(Smartphone image via Shutterstock)