Mashable reports that Twitter will now.

The program, called tailored audiences, rolled out in a smaller scale in July. Using tailored audiences, advertisers can target users who have either visited their website or “shown an interest” in your brand’s category on and outside of Twitter. For advertisers, that means it’s now possible to identify people who are in the market for a product.

Why are people complaining when Google has been doing this all these while with Google AdSense?