The whole point of shipping games and play across the sea is so European teams can expand their brands and market into a market that may not follow them as much. To illustrate this fact you ask anybody in America who their EPL team is and you invariable get 5 answers. Man U, Arsenal, Liverpool, Chelsea, Man City. These teams are world clubs in the top league in the world. Their brand expands across every country. I am an Everton fan. When I talk to people from England they always looked shocked. The point of teams playing an exhibition or Super Cup game here is to expand the brand. The game between Lyon and Mont was very exciting and for anyone that was there or watched on TV now may think to themselves that they should watch Ligue 1 games. Ligue 1 is almost unspoken of in the USA. They played the game and no it was not a sellout but when I tell people about Briand's attempted scissor kick everyone wants to see it and begins to talk about Ligue 1. The influx of money into PSG won't hurt either. I do not foresee regular season games ever being played here.
it doesn't have to be of greater interest than mls. i'm a rbny sth and go to the games. the interest however would exist for the same reason people in tokyo went to see mlb games, or people in prague (iirc) went to nhl games. those people have pretty good baseball/hockey leagues already where the games count.