Carousels are good for things users should be vaguely aware of but are not likely to click on. For example if you have a company that sells a widget, you can have the important menu about buying a widget on the top and below it a carousel of recent news with pictures.
These news can be about your participation in widget related conferences, about you passing obtaining environmental goals, about some R&D project promising some better widget some time in the future, about community involvement of your company etc.
Most customers will not click on those stories and they are not intended to. But they will get a changing site with changing pictures and will peripherally learn that you are a forward thinking socially involved company that is an R&D leader, participates in the community, etc.