Many of the users are not well aware about "twitter's adsense journey", Twitter itself earlier accepted the Adsense on their page but simply removed it later. The adsense ad was not shown of the profile page or the home, it was shown on the internal tweet page under the tweet text. They might have placed the advertisement under the tweet text to catche a good keyword by the Adsense.
The Why later they took away the adsense placing?
There may the following reasons:
- Due to the amount of less text they might have got less contextual advertising.
- 234x60 Adsense format is not a good performing ad format.
- The color of the Adsense background to is not matching to the Twitter's background color.
- They even might got removed by the Adsense itself as it was not up to the Adsense rules and twitter too was not famous at that time.