Almost all erotic massage parlors in Marseille are run by the Chinese. The remainder belongs to the Thais. Those won’t advertise online, but the further from the port the seedier it gets. It’s also where the chance for a happy ending is the highest.
I’d recommend going to a French studio instead that has massage érotique on its menu list. Those might be more expensive that the ran-down Asian spots but you get value for money most of the times. Pleisir des Sens (https://plaisir-des-sens.fr/) at 440 Avenue de Montolivet gets top-notch reviews. Lisa (http://mnbylisa.fr/) at Rue d'Italie offers an amazing outcall massage naturiste. Kailasa (http://www.kailasa.fr/) at 25 B Avenue Pasteur is considered to be one of the best Asian spots in Marseille.