Not just likelihood of success, but also whether any irreparable harm could occur while the case is being decided, in the event the case favors the plaintiffs. In this case, if card companies are only allowed to collect $8 while the case is ongoing, and then a judge ruling they are allowed to collect more than that, means there’s a monetary loss that will have happened. Now I wouldn’t be crying if credit card companies are forced to stop ripping people off, and absolutely fuck the Chamber of Commerce, but that’s what it is.