Facebook is giving lower prominence to web links that lead to pages full of deceptive or annoying advertisements.
Starting today, the company is rolling out an update so people see fewer posts and ads in News Feed that link to "low-quality" web page experiences. Facebook says that the update will help reduce the economic incentives of financially-motivated spammers.
Links to websites with pop-up ads or full-screen ads also would be downplayed, Facebook said.
Facebook uses a computer algorithm to determine which posts people see first from friends and family, and it frequently refines the algorithm to keep up with spam or other concerns.
The company said in August it was adjusting the algorithm to downplay news stories with clickbait-style headlines.
In December, facing criticism that fake news stories spread too easily on Facebook in the run-up to the U.S. presidential election on Nov. 8, the company made it easier for people to report those kinds of posts.
The company did not name any websites Facebook wants to target. But it said publishers of spam needed to worry about seeing less traffic, and other publishers could see their traffic go up.