Now that its IPO is over, Twitter’s mission to expand is moving along at a clip. Sometime next week, the social network will officially launch retargeted ads. Begun as a trial in July, this service will allow advertisers to access browser cookies from your computer, gathering information about the sites you visit to show you the ads – the Promoted Tweets you may have already seen on your feed – to which you are most likely to respond.

“Users won’t see more ads on Twitter, but they may see better ones,” wrote Kevin Weil, senior director of product and revenue for Twitter, in July.

For instance, as explained by TechCrunch’s Josh Constine, if you visit the subscription page of The Financial Times, for instance, you might later see the following Promoted Tweet on your feed, which you might be likely to click because you'd been thinking of subscribing anyway:

Users can opt out of seeing promoted content easily, Twitter says, by changing their preferences towards Promoted Content in the Security and Privacy section of their account settings (I did it in two seconds). But Twitter is hoping that its users find ads for businesses they already frequent useful, translating into more ad sales for them.

Crucially, Twitter’s new service will allow advertisers to use your Twitter account as a pivot between desktop and mobile ads. 70% of Twitter’s ad revenue comes from mobile; retargeted ads will allow advertisers to use information from users’ desktop browsers – where most mindless clicking takes place – to sell them things on their mobile devices.

Introducing retargeted ads may be an attempt on the part of Twitter execs to bring the outside web in, in a new way. Rather than just sharing photos, thoughts, or favorite articles, Twitter might now serve users as a helpful suggestion tool to get what they want – for people who choose to use it this way, at least.