WikiTree has several sort tools to help you find duplicate profiles within your watchlist.
In previous years, WikiTree was not as stringent on uploaded gedcoms. Many members apparently used the same roots and copied public trees from various websites; this created many duplicate profiles. Many of these duplicate profiles have been identified through the past couple of years and merged into a single profile; yet, many duplicates remain. As genealogy advances, more information becomes available on profiles.
If you uploaded a gedcom in 2011, it is likely that you still have duplicates that you manage and these duplicates need to be merged. When looking for potential duplicates: Are one or both parents the same? Is the DOB or DOD and area the same or nearly the same? Are there any primary sources (note: public trees, pedigree files and ancestral files are not primary sources). A good profile's worth is judged on how well it has been sourced. Sadly, the same profile manager names appear when searching for duplicate profiles and this could easily be minimized if each profile manager took responsibility in observing the WikiTree mission of "One Profile Per Individual."
Everyone makes mistakes; finding and correcting these errors greatly enhances WikiTree and also provides a feeling of pride as you have resolved a problem you created for someone else!