As of today, mobile Twitter users will now be seeing promoted tweets show up in their timelines. This should be good news for anyone advertising as our world is becoming more and more mobile.

As with the launch of Promoted Tweets in user timelines on Twitter.com, we started by showing them in the timeline only for those users already following the advertiser. Since we began testing three weeks ago, reactions have been positive. Starting today, we are expanding this test, enabling brands to target Promoted Tweets to mobile users that share similar interests with their existing followers.

Twitter also points out that there will be targeting options for ads, allowing advertisers to chose from desktop to iOS, Android or other mobile devices. This can be really great for companies that are based solely on some mobile platforms, like mobile game and app developers.

Given that 55% of the more than 100 million users who log in to Twitter every month do so at least once via mobile, this expanded roll out of Promoted Tweets in mobile is a great opportunity for brands to connect with more users, more of the time.

As Twitter states, these promoted tweets will be based off of similar interests that you have with the company advertising, so hopefully these won’t become too intrusive. Do you use twitter on your smartphone or tablet? How do you feel about more advertising being put in front of you?