Yeah, but.......
Most of the "mainstream" physical activities and sports don't promote themselves much, either.
The most popular sports and physical activities in Oz are stuff like walking, swimming, aerobics/fitness, golf, tennis, bushwalking, soccer, fishing, cycling, running, tenpin bowling, netball. Despite their huge popularity, only about half of these sports get much TV or other publicity.
So maybe it's not as if "the mainstream" of active people actually get into a sport by seeing it on the idiot box.
God knows why our media refer to cricket, footy etc as "mainstream" sports like they do.
Lots of the big media sports aren't "mainstream" in terms of people doing them. Aussie Rules isn't "mainstream" in participation, 'cause less than 2% of Aussies do it; lots more play lawn bowls, more people play table tennis. Half as many people get out on a canoe or kayak as play Rules, and how often do we see spectacular canoe racing on TV?
Squash gets stuff-all publicity and is played by more people than cricket, which gets lots of TV.
"Surf sports" are supposedly underground but they are actually quite popular in terms of particuipation and even more popular in terms of the members of the public who want to watch them. The ASA boasts about how popular surfing is on TV, so maybe they don't want it to be "underground".
League and Union are supposedly "mainstream" but they are played by just 0.7% and 0.3% of the population at most, according to various surveys.
So again and again, the numbers point out that publicity doesn't equal participation.
Oh, and yes, we have heard all the "lies, damned lies and statistics" lines before!
But surely the way we thnk about promoting a sport should be based on some sort of facts, and these are closer to that than our gut feeling is.