Mozilla, maker of Firefox, roiled the online ad world when it announced its new default setting on upcoming versions of its web browser would block third-party cookies (tracking devices used to target you with ads).
It's less obvious, however, that the move may play into the hands of huge publishers like Facebook, Twitter (and even Business Insider), as well as device makers like Apple.
And that's why advertisers are so angry about Firefox. The IAB called it a "nuclear first strike." Some of them are even thinking of ignoring or subverting Firefox's new policy.
The cookie crumbles
Essentially, the Firefox move weakens the cookie as the sole basis for an ad campaign. In so doing, it strengthens the hand of publishers who will still be able to track users on Firefox browsers. More importantly, it makes so called "native advertising" solutions — custom ad formats used only by companies trying to sell them at a premium to general web display inventory — more appealing as the quality of cookie-based advertising declines.
Firefox would line up behind Apple's Safari browser, which also blocks cookies from web sites you haven't visited ("third parties"), and Microsoft's Internet Explorer 10, which has a default "do not track" cookie command built in.
Only Google's Chrome allows third-party cookies by default — that's not surprising, because the Google advertising environment is heavily dependent on the cookie data its users generate as they surf the web and respond to ads and search results. Users are tracked by cookies from web sites they have visited ("first-party" cookies) and from advertisers who have been invited to target those users after they arrive on a site ("third party cookies"). Putting the two types of cookies together allows advertisers to slice and dice audiences in clever ways, based on their interests as extrapolated from their browsing history.
But in recent years, more and more money has poured into "native advertising." Facebook, for instance, has built a $5 billion ad business using a series of display formats that look nothing like traditional web banners. It is not a cookie-based system.
Facebook and Apple are not dependent on cookies
Facebook does have a cookie advertising business — its FBX ad exchange allows advertisers to target users inside Facebook with cookies from third-parties. But FBX is still only a portion of Facebook's ad revenue. Its most lucrative business is probably its mobile advertising and news feed sales.
Twitter recently launched its Ads API interface, allowing advertisers to plug their own ads into the tweet system. That's not dependent on display-driven cookies, either.