The advertising service was initially implemented via the third party client – HootSuite. The program is committed not to spoil the Twitter experience and to prove sustainability to advertisers, who will promote only to relevant users.

The San Francisco-based company’s CEO, Dick Costolo admitted in April that Twitter intends to add selling advertising into a user’s timeline by the end of the year. This process is to be a progressive one, without harming the Twitter user’s delight.

Back on time, the first step to this actual escalade was the introduction of Promoted Tweets, which appeared on Twitter.com searches or users of HootSuite and TweetDeck. The new timeline ads will function of an extension to the Promoted Tweets.

If in May the company banned any third party clients from introducing paid tweets, now the publishing of ads in users’ stream is planned to be done at a smaller scale – 175 million users. If the project will turn out to be successful, then the timeline ads will be expected to roll out on other Twitter readers.