View Performance of AdSense Link Units without Setting Up Channels
Maybe this is the reason why AdSense dashboard was down for some time over the previous weekend - they have added a new feature under Advanced Reports that lets you separately view the performance of your link units.
Earlier, the data of Link Units was always combined with that of regular Ad Units and AdSense publishers therefore had to setup channels for tracking the performances of individual units.
This has changed now but you may still need to use channels if you have setup multiple Link Units on your website.
Related: See situations where Ad Link Units are very effective.

Thanks for the information. I wonder if a report can be saved for link units, so that a daily e-mail can be sent to publishers?
Dear Amit,
Thanks for this informative article. After reading your post I checked the above data for Ad units & Link units for my Blog & site. Interestingly Link units are hardly performing, while it is showing as a major part of my page impressions in my adsense account. Should I remove Link units altogether as these are hardly performing?