“Marketing on Facebook doesn’t work very well, and marketers can’t count on things improving anytime soon,” write Forrester interactive marketing analysts Nate Elliott and Melissa Parrish in a new blog post published just days before the social networking company’s initial public offering.

Forrester’s take? Facebook needs to focus on the needs of marketers to the same degree it has served users. As Elliott and Parrish write, “One global consumer goods company told us recently that Facebook was getting worse, rather than better, at helping marketers succeed. And companies in industries from consumer electronics to financial services tell us they’re no longer sure Facebook is the best place to dedicate their social marketing budget — a shocking fact given the site’s dominance among users.”

Read more of the analysis in this blog post.