Simply put, I think that the Armenian genocide was able to show Hitler that his ideas could actually work. The idea of employing nationalism could be parlayed into the removal of an entire group of people. The "Young Turks" who were able to seize power did so on a premise of nationalism, being able to blame the Armenians along with economic and political liberalism for Turkish woes. This is something that Hitler was able to do in terms of identifying the problems with Germany as converging both on "enemies of the nation" and the weaknesses in liberalism.
Another similarity that must have influenced Hitler was the organization of the nation as a killing machine. The Turkish creation of different units whose primary purpose was to eliminate the Armenians was something that must have left an impression on Hitler, as he did the same thing in Germany. "Special Organization" designations as well as "killer units" of the government were discharged with removal of the Armenians.
The very idea that the Turkish government could annihilate an entire group from memory without any audible response from the rest of the world is something that must have lingered with Hitler, who once remarked, "Who, after all, speaks today about the annihilation of the Armenians?" In the end, this quotation might speak quite loudly in explaining how the Armenian genocide impacted Hitler.