Barton has thanked the club for easing his transition into new surroundings and is now hoping to help pay them back on the pitch.
"I thought that integration would be more difficult in French football, the French culture and way of life, but it was facilitated by the club," he told Marseille's official website.
"The staff and players have been incredibly welcoming. It's like a family. Everyone helps everyone, people talk, say hello, are kind and friendly.
"Many clubs are not like that. Where I come from, there are many clubs where the players and the staff are separated from the rest.
"The club has helped me tremendously and this has made my life easier.
"The team has already won six league matches, so it will not be easy for me (to make the starting XI).
"There are some very good players here, but when you want to be a big club you must have a team of 15, 16 or 17 players. All players cannot play every week and I hope to bring something different to the team and become an important member."