Google’s Danny Sullivan has revealed that carousels of web forum posts appearing in search results are an optional feature.
Forums that display such carousels in search results have explicitly opted-in to the feature. It’s not something that displays automatically.
This may explain why it’s shown for some forums but not for others. Reddit is a popular web forum that supports carousel previews. Stack Overflow is another.
You can see an example of this feature below in a GIF captured by Marie Haynes:
If you run a forum site, this is something scary. Google is now showing a preview of forum posts making it unnecessary to click through in many cases. pic.twitter.com/UAL0wrh5qw
— Marie Haynes (@Marie_Haynes) August 14, 2018
In her tweet, she expresses concern that this preview may eliminate the need to click through to the forum post itself.
Her tweet triggered quite a discussion on Twitter, which led to Google’s own Danny Sullivan chiming in to clarify that carousel previews are only shown for a few sites that have explicitly opted-in.
This only happens with a few sites that have explicitly opted-in to the format.
— Danny Sullivan (@dannysullivan) August 14, 2018
That doesn’t negate the concern regarding this feature leading to fewer clicks.
However, if that ends up being the case, then the websites technically only have themselves to blame for opting-in.
With that said, if the feature does negatively affect traffic, then all a site has to do is opt-out.
This is one of Google’s few types of search result previews that are opt-in only.
Most recently, Google introduced a type of preview that displays expandable featured snippets. These snippets display a considerable amount of automatically generated content.
So, if web pages receive less traffic as a result of being featured in expanded snippets, they cannot simply opt out.
For what it’s worth, it appears that Google’s own web forums have not opted-in to carousel previews. I’m not sure if there’s anything to take away from that, but I thought it would be interesting to note.