By definition, a persona is the type of character that someone appears to have. In this context, a persona is something that a content creator projects through the content they create and how they present it to the audience.
Good content creators have a certain style, which is often attractive or memorable or quirky in some way. It is not exactly their true self -- it is a "character" or "personality" that they have created to attract an audience. If you go to YouTube, many videos feature people who are quick, witty and humorous. But videos can also be very serious in tone. It all depends on what is being communicated and how it is being presented. The quote above is saying that Giftto helps these people make money using the characters they have created for their online presence.