[DS reporting API] unattributed keywords coming soon

[Dustin Tseng]

In a few weeks, DoubleClick Search will introduce reporting on unattributed keywords. Unattributed keywords will be identified by having a keywordId attribute of 0.

Keywords may be unattributable for a number of reasons. One of the more common cases occurs due to differences in how DoubleClick Search and AdWords handle recreated keywords. See "What are unattributed ads and keywords?"