Lately, Mashima has been giving us a lot of double chapters. He will reportedly have double chapters for four consecutive weeks (starting week of April 22, 2015 with chapter 429). At first, I thought it was related to Golden Week, but that does not last four weeks. Does anyone know why we are getting four double chapters?
I think this is mainly a marketing tactic, meant to attract more readers to buy copies of the Weekly Shonen Magazine1. When the magazine's copies hit the bookstore, a front cover caption Fairy Tail! Double Chapter inside!! ... and next 3 weeks too!!! (or something on those lines) will draw the buyer's attention, and would likely lead to an increase in sales.
Regular readers would buy the magazine no matter what, but the tactic is mainly aimed at two categories of prospective buyers:
- New buyers, that is, people who have never bought (or perhaps, even heard of) the magazine before.
- Buyers who are unsure if they should buy the magazine.
People are made to believe that they are getting something "extra", which often leads to making a buy decision. This, by the way, is not much different from the "Buy One, Get One Free" offers. It is also quite common for popular TV shows to have "2-hour specials" every once in a while, which is also based on the same "principle" (if you will).
Moreover, announcing 4 consecutive editions with double chapters increases likelihood of repeat business. People look forward to buying the next 3 issues as well. Buying 4 consecutive issues will lead to at least a sizeable number of readers "latch on" to the magazine, who would naturally choose to continue buying later issues as well.
As for why Fairy Tail gets double chapters so often (as against other mangas), I think it mostly comes down to "because he is
Erza Mashima!!" To elaborate, Mashima (and his assistants?) are able to spend more time and/or effort on their manga and can submit two chapters in a week, whereas most other mangakas may not be able to do so due to personal commitments or other reasons. As an aside, he published triple chapters of Fairy Tail for two consecutive weeks a year or so ago. (Chapters 338-340 and 341-343, IIRC)
1 Weekly Shonen Magazine is different from Weekly Shonen Jump.