Facebook will penalize posts linking to web pages that deliver a poor experience by not surfacing them in the newsfeed.
Facebook started rolling out an update last week designed to prevent people from seeing posts that take them to low-quality website experiences. They've announced they will be penalizing the organic rankings of these posts so they appear far less in the newsfeed, and they will be stepping up the enforcement of rules on ads that prevent people paying to advertise spammy or malicious sites.
Facebook announced they are doing this because their users are unhappy with being taken to sites which are just 'click-bait' designed to draw visitors in and then get them to click on an ad. In an official statement, Facebook reported that:
We hear from our community that they’re disappointed when they click on a link that leads to a web page containing little substantive content and that is covered in disruptive, shocking or malicious ads. People expect their experience after clicking on a post to be straightforward.
What counts as a low-quality website experience?
As we can see from Facebook's commentary above, any site with large numbers of disruptive, shocking or malicious ads will be penalized, as will those with 'little substantive content'. Essentially this is 'click bait', anything that over-promises and then fails to deliver. Facebook provides a list of what this constitutes in their ad guidelines, so you absolutely need to avoid doing any of these things.
How will this change affect me?
So long as you aren't using click-bait tactics, this change should be good news. Those who are abiding by the guidelines should see slight traffic rises as the demotion of spammy content in the newsfeed will allow your content to surface in the newsfeed more easily.
Facebook have stated the changes to the algorithm will be being rolled out gradually over the course of this month, so you are unlikely to see any sudden changes in your engagement rates. If you have used tactics such as ad formats that disrupt the user experience or high ratios of ads relative to content then you need to stop immediately, before you start getting downgraded by the rollout currently in progress. If you don't you will see your engagement fall off a cliff, as Facebook makes these tactics counter-productive. Don't say we didn't warn you.