Twitter is reportedly working on 15 new types of ads that will appear in users' feeds in the coming months, sources revealed to Wall Street Journal.

Twitter is expanding its commercial offerings with 15 new ads that will adorn user's busy twitter feeds. The new ad system will allow advertisers to download apps directly from Twitter with the help of its recent Cards-integration, which embeds a link for the users to download the apps. The unofficial news came after sources familiar with the matter confirmed to Wall Street Journal that the social networking site is devising new ways to target users.

 Ad revenues are important for companies like Twitter and Facebook to make quick profits. Twitter more than doubled its ad revenue during the fourth quarter of last year to $219.6 million compared to previous years. According to the WSJ report, Twitter is already internally testing a Facebook-style mobile-app install ad unit. As it uses Twitter's card technology, once a user clicks the "download" button embedded within an ad, they will be redirected to the App Store. Once downloaded, users will revert back to Twitter.

Some of the ads that urge users to download their apps have already appeared on user's Twitter feeds. Ads from mobile-payments company Square Inc., Digital-music streaming service Spotify AB and Japanese mobile gaming company Gree are already seen on the site.

For Facebook  this strategy, which it introduced in 2012, has been quite successful. More than 245 million mobile app downloads in 2013 originated from its mobile-app install ads, which was a major part of the company's ad revenue.

Other types of ad formats will also use Twitter's cards feature to connect consumers with companies. According to WSJ, Twitter has been experimenting with "click-to-call" button to engage users with its shoppable Twitter ads. The company is reportedly in talks with Stripe Inc, the payments processing company.

Advertising is a sensitive subject and Twitter has played safe in this space so far. The company introduced its first advertising product in 2012 and has contained the number of ads served on users' timeline. With the 15 new types of ads, Twitter needs to manage them in a way that will not tick users off completely.