The goal in publishing is to publish more books that people will buy.
For example, say Marvel can publish 50 books a month. Then sales of New Avengers go up because people really like that book. Sales are so high, that Marvel can start a new comic called Mighty Avengers. Now they publish 51 books a month. Then they see that Spider-Man sales are high. They decide they can publish it twice a month and give fans what they want. Now they publish 52 books a month. Then sales of Uncanny X-Force are high, so they double ship that book too, and create a new comic called Uncanny X-Force: First Class. Now they publish 54 books a month.
THIS IS HOW YOU WORK IN PUBLISHING!!! When Marvel publishes more books per month, it is because their sales are high enough that they can.
It is not a dirty trick! Understand the industry before whining and complaining.
Now can we PLEASE stop the "They only sell more because they publish more books." THAT IS WHAT THE PUBLISHING BUSINESS IS! You sell and publish more books because you can! Because sales are high, and you need to move as many books as possible!
If they sell 52 books a month, and each sells an average of 100,000 per month, they sold 5,200,000 books that month. By publishing a new comic, that is 53 books, and they sell 5,300,000 books that month. That is how the business works and how you succeed.
And why don't other companies publish as many books as Marvel? Because they CANNOT. Because their sales are only high enough to sell however many books they have. If Image sells 20 books a month, they want to do what they can to make sales rise and sell 21 books a month, and work their way up as high as they can. Thats the business.
And how many more books does Marvel publish than DC per month? Not that many.