Facebook marketing is changing… again. This time the tweaks are to the way advertising campaigns are structured on the social network. The current two-tier system of campaigns and ads is getting a third tier: “ad sets”. Campaigns will correspond to specific advertising objectives, and each can have multiple ad sets with their own budgets and schedules, representing different audience segments if the advertiser so desires. And then within each ad set, there will be multiple ads. “Though these updates won’t begin rolling out until March 4, we want to make sure all our advertisers and partners know in advance that this helpful change is coming,” explained Facebook in a blog post promising that the new system “will make it easier for advertisers of every size to organize, optimize and measure their ads”.