Google launched Adsense Direct 9 months ago as a way for Adsense publishers to sell their ad space directly to advertisers. When the idea first came up everyone loved it, it was meant to be the easier version of DFP. However, the idea was a total flop because of poor implementation from Google. Google only allowed advertisers to pay with Google Wallet and they had strict rules on the range that you had to pay for campaigns.
A post on the webmaster world forum shows the full email.
Thank you for participating in the early trial program for the AdSense Direct link. After analyzing the results of the initial testing period, we’ve decided not to move forward with this beta feature. We want to thank you for trying it out and giving us your valuable feedback throughout the process.
We recommend that you remove the URL for the AdSense Direct link from your site or sites by November 25, 2014. Advertisers will no longer be able to book campaigns through the AdSense Direct link after this date.
We are constantly working to improve the AdSense product to provide you with the best experience possible. Stay tuned for new trial opportunities!
Sincerely, The Google AdSense Team
If you wish to speak your mind on this subject discuss it at the webmaster world forum.