If all goes well, one of the traction channels you tested in your inner circle produced promising results. In that case, you should start directing your traction efforts and resources towards that most promising channel.
At any stage in a startup's lifecycle, one traction channel dominates in terms of customer acquisition. That is why we suggest focusing on one at a time, and only after you've identified a channel that seems like it could actually work.
The goal of this focusing step is quite simple: to wring every bit of traction out of the traction channel. To do so, you will be continually experimenting to find out exactly how to optimize growth in your chosen channel. As you dive deeper into it, you will uncover effective tactics and do everything you can to scale them until they are no longer effective due to saturation or rising costs.