Upper panel: mass-period diagram with brown dwarfs companions detected through radial velocity, transit and direct imaging (blue filled circles for measured masses, and open circles for minimum masses; list adapted from Ma & Ge 2014), and microlensing (green diamonds). For reference, exoplanets detected so far are also displayed (small black circles, http://exoplanets.org). The red dotted line indicates the global radial velocity completeness limit, while the red dashed line marks the region above which data are included to perform the non-parametric, two-dimensional probability density distribution shown in the lower panel.