XMR has achieved what it has achieved with very little marketing, and no official GUI.
It has done this because its cryptography and tech is top notch.
Hordes of pumpcoins with ICO funds to spend on marketing have been unable to achieve a higher market cap than it, only a few are above it, most of which are other very solid coins. Monero is up with the elite.
It is certainly having a good run. The market cap is minuscule at this stage and the privacy features are a strong buying point.