If eyes on your content is your concern, you’d be wise to question whether Mixer is the right platform for you with its present userbase. Microsoft hasn’t announced any concrete numbers for the fledgling service, which had only been around for six months before Redmond snatched it up, but even its top channels don’t exceed more than a few hundred viewers.
You’d imagine that YouTube, the most popular video service in the world, would mean big numbers for streams, but that’s still not necessarily true. Users with an existing name and reputation can attract a hefty viewership, it’s true, but YouTube’s live offering is still finding its feet, and realistically you’ll need to attract subscribers before anyone will stumble on your live output.
Twitch’s growth has slowed due to increasing competition, but it certainly hasn’t reversed. Its top streams (admittedly, these are large esports events) have broken a million concurrent viewers, and even the top solo streamers have been able to attract a quarter of a million eyes. It’s also a lot easier to discover new streamers on Twitch, and its users will habitually search by game—a handy driver.