London, should they survive, really need to take a step up off-field though, and Super League should help them, particularly with marketing.
Get a star NRL player in, someone who draws in fans and they can build a roster around, and ensure they stay off the bottom.
London and Super League both start targeting advertising to the expat Aussie and Kiwi population in London, get that average at Ealing up around the 3000 mark. That would show some good growth.
Get one of the end of years tests v Australia in London, and piggy back off that. Sell and promote Broncos season tickets at the game. There will be 40,000 people half of who probably don't even know the Broncos exist.
Begin planning a move to a bigger stadium closer to the city. Their ceiling at their current home would be 3500 which would still leave them with the worst attendances in the league.
Start with 1 game a year, market it hard as a special event.
Every year needs to show growth on the year before.
London is important but a tiny, stagnant Broncos achieves nothing.