AdWeek reports mega credit card firm Capital One is putting up its online media account into review, seeking to consolidate six media buying firms to just one. Current roster members - which include Mediavest, Reprise Media, Page Zero Media, Marketleap, Questus and Advertising.com - are quite diverse, ranging from search engine marketing firms to technology consultants, ad agencies and media companies. All incumbents decided to join the review, handled by Boston's Pile and Company.