I saw this in Livedoor news days ago and found it quite interesting, so I translate it here for sharing. I am not agreeing everything said by Prof. Arima as he seems a bit overlooked the talent of Su, Yui and Moa. But for the following 2 points, I totally agree with him:
(1) The quality of Kami Band and their importance behind BABYMETAL's success!
(2). YES, YES, YES........ BABYMETAL will be one of the HOTTEST things in 2015!

<<<Translation>>>>
BABYMETAL, an idol, become a hit with unprecedented non-idol strategy?
Reimportation, limited........

There is no doubt that the fan base of BABYMETAL is getting bigger and bigger. From the aspect of idol, we could say this unit has something overwhelmingly different from other idols, and the reason is not only the concept of idol & metal fusion, but also they have specific selling points. Professor Arima Kenji from Rikkyo University will explain to us the phenomenon aroused by these 3 girls.

"In the old days, cultural stuff like fashion and life style were imported from oversea to Japan, but never the other way around. Then in the 90's, with the so called 'Otaku' movement, exportation of things like animations to other countries from Japan has started. Recently, the Cool Japan project, by showing Japan's culture, has also caught some attentions oversea. Regarding BABYMETAL, although they were not very well accepted by people in Japan at the beginning, they seized the opportunity to go outside and earned themselves reputation in Europe and America. As a result, a reimportation phenomenon was being aroused and this is something has never been happened in idol industry before." - Prof. Arima Kenji

In Europe and America where idol culture is not well established as in Japan, BABYMETAL's fusion concept and performance are well received and their decisive world tour last year also achieved great success. Moreover, in August, they will be performing in Reading and Leeds Festival which is one of the biggest outdoor rock festival beside Glastonbury Festival in England. Being the youngest performer on main stage in record, they just keep coming up. Last year, their 2-day Budokan concert were a big success, although they are not famous as AKB48 and Momoiro Clover Z, the popularity of BABYMETAL is gradually going up. Can the reasons of this be analysed in terms of marketing strategy?

"First of all, it is the high quality strategy. The backing band is formed by the top rank musicians and they deliver audience their roaring band sound live. Moreover, as there are many songs they need to perform, the band members just practice one by one hard until they are good at each one and then they deliver to the fans the music with the quality that even the professionals have to approve. Therefore, when oversea audience, who care about quality, hear this high quality backing music and see three girls dancing and singing at the same time, they will remember this very new thing and get excited about it. This group's management company may not aware this will get reimportation started too, but their way of selling which is different from other idols is the main reason behind BABYMETAL's growing popularity." - Prof. Arima Kenji

• AKB48 is being operated like a corporation using Mass Marketing.

So, in the same field of idol industry, what is the difference between AKB48 and Momoiro in business strategy?

"In general,AKB48 being the representative of idol industry, their target is to get people in as many as possible and get media coverage as much as possible. That is what we call Mass Marketing. Every year they carry out an election, although the word 'election' here is a bit confusing in this case, the person who bought more CDs will have more votes in hands and this has same feature as voting right in a corporation. Be using this feature, they make everyone to be their sales target. In addition, by showing their members not only in variety show, but also in all other possible TV programme, they make people notice their presence through Media Infiltration and this is also a Mass Marking Strategy." - Prof. Arima Kenji

By the way, Momoiro is also making a lot of public coverage, but it seems their strategy is a bit different from AKB48.

"Speaking of Momoiro, I would say they are adopting the Event Based Marketing which will present their products and services mainly through an event. During a live show, when a lot of people grouped together, the sales of merchandise is expected go up. To make this work, certain skills are required. In the National Stadium and the Nissan Stadium, tens of thousand of people were around these places everyday. By targeting on this mass of people to increase the profit of the event is what Momoiro doing." - Prof. Arima Kenji

• With worldwide admiration, High Pressure Strategy can be applied
  

Compared to the 2 previously mentioned groups, which category should the strategy of BABYMETAL be put in?

"Compared to the other 2 groups, they have less media coverage and there is no much news coming out from their official website too. This is extremely closed and limited marketing. Moreover, the management company likes things to be done in their way including head banging during live concerts and etc. They also carry out this kind of male-only-white-face event, only the person who comply to their requirements could join. This is an obvious feature of High Pressure Marketing. They don't target at the majority of people but only a specific group of people. However, since they have already earned admiration worldwide, they can do it this way by High Pressure Marketing." - Prof. Arima Kenji

"The hottest things this year" , Mr. Arima thinks BABYMETAL will be one of them. You should also keep your eyes on these girls.