Five years ago, MLS had 15 teams. By the end of the decade, it plans to have 24. Minnesota becomes the league's 23rd expansion market; Philadelphia, Vancouver, Portland, Montreal, New York City FC and Orlando have joined since 2010. Atlanta (above, from left, city mayor Kasim Reed, MLS commissioner Don Garber and team owner Arthur Blank) and Los Angeles are set to begin play in 2017, and Sacramento and Miami are vying for the league's 24th club.
Kevin Liles-USA TODAY SportsKevin Liles
One of the most unique elements of an MLS game -- or any major professional or international soccer match, for that matter -- is the nonstop energy reverberating around the stadium, supplied primarily by large supporters' sections that cheer, chant and sing throughout the game. The best gameday experiences include Sporting Kansas City's Sporting Park, Seattle Sounders FC's CenturyLink Field (above) and the Portland Timbers' JELD-WEN Field.
Jennifer Nicholson-USA TODAY SpoJennifer Nicholson
It's got star power
Clint Dempsey. Robbie Keane. Bradley Wright-Phillips. MLS isn't as fraught with superstar talent as its European brethren, but there's plenty to go around. Dempsey (above), the United States captain at the 2014 FIFA World Cup, plays for Seattle Sounders FC. Keane serves as captain for the Los Angeles Galaxy and the Irish national team. And Wright-Phillips, an Englishman and former Manchester City player, led the league in goals last year with 27.
Isaiah J. Downing-USA TODAY SporIsaiah J. Downing
It's (relatively) affordable
According to data from Forbes and statista.com, the average MLS ticket price falls right in the middle among the five major American professional sports leagues. The average MLS ticket cost $56.89 last season, compared to $84.43 in the NFL, $62.18 in the NHL, $53.98 in the NBA and $27.93 for MLB during their most completed seasons. In most MLS stadiums, a decent seat can be had for around $35.
Jerome Miron-USA TODAY SportsJerome Miron
It's a long season
The MLS season starts in March and doesn't end till early December. Divided into the Western and Eastern Conferences, teams play 34 regular-season games before a 12-team MLS Cup playoffs. In addition to a midseason All-Star game, clubs break from their regular-season slate to participate in other competitions, including the CONCACAF Champions League and the U.S. Open Cup. Unlike most soccer leagues worldwide, MLS doesn't use a promotion and relegation system.