If scientists hear about a platform where they can talk about their work and earn more than minimum wage on it? Word of mouth alone will bring many on. Visiting the LHC with steem tags everywhere will spark interest. And since the science community is interconnected, everyone can bring their friend on.

Most journals you pay for the right to publish. Here you are paid. Being a welcoming and supportive community like steemSTEM means the users come on their own, one small nudge to tell them it exists is mostly enough.