Wall Street Journal: Just two months ago, Hulu responded to competitive pressure by rolling out an ad-free option. Now, it’s responding in a different way, but rolling out a new ad format that viewers choose. To start out with the new ad format, one of the “engagement ads” developed by 21st Century Fox ad tech subsidiary TrueX, will only be on Fox programming on Hulu, but the option will be open to any other media companies.