According to Insight Crime, the CJNG's meteoric rise to power since 2010 is due to a convergence of factors. The group's origins within the Sinaloa offered them business opportunities and practical knowledge. And the relative stability of Jalisco state enabled the group to expand and consolidate without having to engage in costly turf battles to establish initial control. The relative weakness of cartels in neighboring states also allowed the CJNG to expand outwards without much resistance. 
The CJNG has also expanded successfully thanks to its past strategy of portraying themselves as a nationalistic paramilitary group aimed at defeating other cartels and bringing stability to the country. 
In 2011, a faction of the CJNG called the Mata Zetas (Zeta Killers) carried out a mass execution of 35 people in Veracruz that the group claimed were members of the rival Los Zetas cartel. Two days later, an additional 11 bodies of Zetas that the CJNG were suspected to have executed were found around the city. 

In a video posted online after the executions, members of Mata Zetas claimed that "our only objective is the Zetas cartel," and that the Mata Zetas were "anonymous warriors, without faces, but proudly Mexican," the Wall Street Journal reports