To gain a large audience, you'll likely have to do a good amount of advertising, with a lot of it being online. Make sure to spread it out as best as possible to avoid spikes in traffic (when you go from very few visitors to very many visitors in a very short period of time). Advertisers don't like to see spikes. Spikes in traffic usually signal an unwelcomed anomaly, like a sudden run of robot (fake) traffic, a hacking attempt, a server glitch, or some other problem. Plus, large spikes in traffic can cause problems with ad servers by sending too many ad requests at once. Instead, advertisers like to see steady but growing traffic rates. If you have too many spikes, chances are the ad exchanges will hold back on serving ads until the traffic levels out a bit.