They try to get you to submit articles to them (usually for a fee too). But they're kind of sham journals with no peer review or standards who no one actually reads. They'll publish pretty much anything without even looking. They have bots that just mass email every corresponding author in every paper published just begging for submissions to their journal. Whenever an article is published in a reputable journal, one author has to have contact information publicly listed so they can answer any questions about the paper, and these predatory journals just scrape that info. It's bad, so many emails every day.