The seven-year study, conducted using Accenture's Web Evaluator tool, scrutinised the user experience of 300 consumer-focused websites of the world's largest companies.
Eighteen per cent of web pages of the top websites have not been tagged with java script tags, or have been incorrectly tagged, found the study, meaning that almost one fifth of web publishers' traffic numbers were inaccurate.
Meanwhile, twenty-two per cent of ads running on these sites were incorrectly implemented, reported Accenture - so advertisers have not been properly serviced and media owners have been missing out on ad revenue.
Although company names were not revealed, sportswear companies were ranked top in terms of consumer experience by category, followed by software, PC notebooks and telcos. Automotive, hotel and airline brands were bottom of Accenture's top 10.
Fortune 500 websites carry porn links: Accenture study
GLOBAL - A survey of Fortune 500 company websites by Accenture has revealed that almost one quarter of sites breach privacy standards and four per cent inadvertently carry links to pornographic content.
