There's several different factors that come into play with these things, it's the same for all sports.
First of all, venue matters in LA.. It just does. Kings attendance, despite being a bad team for decades, was never terrible, after they moved into Staples. Their current sellout streak started in early 2012. Winning has obviously helped the sellout streak.
Second of all, winning matters. The Kings were always in the 90% for attendance, but when they started winning? Sellouts.
Third, dealing with transplants. The fact is that LA is filled with transplants. The big draw teams like the Eagles or the Cowboys, or the Steelers or Patriots are always going to attract a ton of fans who are willing to pay a premium for seats. Chicago Blackhawks always have tons of fans in Staples for Kings and Blackhawk games because those fans pay a lot of money to get tickets from the season ticket holders. That's just going to come with the territory, the fans in the stadium help drown out that noise though.
Fourth, finally because we're a destination city, a lot of fans from other cities will buy tickets for a game late in the season and plan a vacation around it. That's how how it shakes out when you live in a nice city, people from colder regions are going to look to travel here for a break from the cold and a football game.
When the Inglewood Stadium is built, the place will be rocking, the dome is going to make that place really loud.
Seattle gets praise for their 12th man, but a few years ago the LA Kings had a playoff game that was so loud the announcers stopped trying to talk, you literally could not hear anything else, both on TV and in the venue itself. It was fucking nuts. That'll happen with the Rams pretty soon, it just takes a little bit of time.
