Alexa as a reliable and consistent source for traffic monitoring.
lexa rankings was often caused due to Safari, Chrome or Firefox browsers not supporting the Alexa toolbar. Alexa's browser plugins or extensions were often incompatible with latest browser versions. Webmasters were the only ones to suffer, never Alexa!
SEO agencies rarely place trust in Alexa rank due to the fact that it can be easily manipulated manually.
So, Alexa rankings are just waste of time and I suggest you to do not waste your time increasing alexa ranks, instead work for great content and content marketing strategies.