The primary purpose of the ResearcherID is to help disambiguate authors with similar names and/or similar research areas. Persons with common surnames (Johnson and Smith are common in the U.S., and Li, Zhang and Chen are most common in China according to http://www.mandarinhouse.com/100-common-chinese-family-names) may wish to create a ResearcherID profile and put citations to their works in the reference lists.
The secondary purpose of a ResearcherID is to help you track citations to your published works, if you include them in your profile, and especially if they are in journals that are indexed in Web of Science. A third purpose is to help you find collaborators with interests in common or complementary interests.
Scholar Universe is another product, through ProQuest, that works very similarly to ResearcherID. An individual can make a profile or edit what is there. It may require that you or at least your campus has a subscription to the databases involved.