The advertising industry rallying around improving the quality of data to target ads continues to make improvements to processes and techniques. Google began rolling out a remarketing tool in Google Analytics on Friday to help marketers gain insight into targeting ads. But if the brand's data mixed with inadequate information from a third-party data seller,  a company's retargeting strategy will deliver less than stellar results. At Guthy-Renker, Colette Dill-Lerner, vice president of Internet marketing, said she has looked at data files "where nearly 50% of the gender is wrong." Some marketers think this characteristic remains one of the most difficult to identify. Aside from gender, other discrepancies exist in third-party…