While fan base seems like the obvious answer to the question of what has had the most impact on the modern comic book industry, I firmly believe that is what keeps the industry alive. When Jason Howard visited the classroom he mentioned that he has spoken with many fans that did not like his comic when they first started reading it, but after following the comic they began to enjoy it. I think this is an excellent example of the persistence many comic fans have. While plot and illustration strongly impact the reader’s willingness to buy a comic, I think it is ultimately up to the reader to invest their time enough to care. It is like watching a television show; if someone does not like one episode of a television show but continue watching it, they may get hooked on the series anyway because of the plot. But ultimately it is the consumer’s decision as to whether a plot is worth following.
There are a million different answers to the question asked, but I think that without the consumer fan base none of the other factors matter. Each person has a different perception of what makes a good comic; some like art, some like plot, some like action, etc. Because consumers have different opinions of what makes a good comic, it is hard to say a storyline is the most important part of the industry because to someone else the storyline may be the least important factor of a comic.
Without an established fan base no comic would survive, let alone the industry itself. The fans are what keep the industry alive and without them and their interest in each comic the industry would die. That is the beauty of the fan base, because each person has their own opinion of what is good and bad in a comic, there are so many different types of comics. Without the opinion of fans comics would be boring and too similar to one another.