Third-Party Trademark Usage and Likelihood of Confusion

When identifying and collecting evidence of third-party trademark usage, the focus should be on obtaining high quality evidence and not merely pulling together all references that may resemble the cited mark. Evidence of actual third-party use is generally accorded greater weight than evidence of third-party trademark registrations. And it is important that evidence of actual third-party use be for use in the United States and not foreign counties. 

Third-party trademark applications, particularly intent-to-use applications, are generally not helpful. Further, even where evidence of actual use in the U.S. is obtained, it is critical that such third-party use be for the same or highly related goods or services than those with which the cited mark is used.

Source:  IPWatchdog