Not to be confused with Influenza an influencer is, in marketing speak, someone that uses social media outlets as a brand advocate alongside of niche promotion of products. I suspect this is the case here, judging by the Smith Micro application form asking you to supply the amount of followers you have on Facebook, Instagram and Twitter. From what I can tell, think Poser Ambassador with a focus on promoting Poser or other Smith Micro products for perks through social media.