I thought so. But I noticed the following in the Twitter blog recently
Now, we’re set to experiment with a way to make ads on Twitter more useful to our users in the United States by displaying promoted content from brands and business they’ve shown interest in. These tailored ads are based on information, such as browser-related information (a browser cookie ID), that our ad partners share with us. Learn more in our blog post here.
While we want to make our ads more useful, we also want to give users simple and meaningful privacy options.. Simply uncheck the box next to “Promoted content” in your account settings, and Twitter will not match your account to information shared by our ad partners for tailoring ads. This is the only place you’ll need to disable this feature on Twitter.
So, they are going to start serving up ads based on content that you have shown interest in, but they give you the option to turn it off…which is nice.
Of course I would prefer if they turned it off by default but, of course, 99% of people will never change that option. This is a good move for them – they are the good guys because they give you the option, but the amount of ad revenue lost is small. Smart.
Of course now that you are informed the power to limit ads is in your hands…use it wisely.