In my case, i bought everything they released, the CDs, the deluxe, the LP, the DVD, and the wallmart and target versions. Not the case because of the price and the fact they didnt do shipments to another countries different to USA. I do think the expectations were too high, but the major reasons of the low sales are (in my opinion):
1- The promotion.
I mean there is a difference between a huge promotion and an intelligent promotion. We, the fans know the promotion was huge, but totally disconnected and totally unarranged. I live in Colombia and the Pepsi cans never came here, so i asked friends to buy those, but for them was really difficult to find them, just in wallmarts, no displays, they had to look for them or ask for them (talking about USA). And exactly the same thing with the product. Just the real fans knew about Bad 25, but other people had no idea. I asked here in the record stores and they didnt have any idea about it. Spike Lee documentary was kind of late, i never saw an advertising in TV (just snippets in fan bases).
2- Lack of credibility
Sony has to understand they did a huge mistake with "Michael" album, and all the suspicious about if Michael really recorded those songs. We know they didnt touch the unreleased songs in Bad 25 (BIG THANK YOU FOR THAT), the truth is Michael's fans still think Sony just want to make money with Michael's name. There were campaigns in Michael's fanbases asking not to buy Bad 25 because Michael wouldnt have wanted that
3- Money
I pre-ordered everything in Amazon, because at the end of the day, i didnt know why so many releases, so i didnt want to miss any of it. Core fans will buy it all but the price was high for regular buyers, if they can download songs or buy 2 or more CDs of others artists with the same money.
4- Singles Promotions
I will never understand why they never released the singles, all of them are GREAT !!! For the regular people, Bad25 was just the same Bad CD, they didnt even know there were new songs. They didnt even change very much the cover, so it doesnt even look like a different CD. People doesnt think they are buying something new, they can pass by saying "i already have that album".
5- The quality
Some fans like me pre-order everything, and others wait to see what others fans say to start to buy. The DVD was a great choice, but i think people was expecting better quality, i mean, at least better than the footage we normally see in youtube. They released a lot, DVD, CDs, Deluxe, different editions in Wallmart, Target, the Case. People was too confused about what to buy.
6- Originality
Michael is ONE OF THE KIND and he knew how to give always something different to his fans. I love all what i have buyed of Bad 25, but they have to start to give something different to the fans, something they dont have.
7- Michael is not here
When the artist is gone, the fans dont feel the same, i mean about the charts, why to bother if Michael is not here to see it. And unfortunely there is noone to speak for Michael to actually promote the album, for the fans be certain the Estate approves it. At this point fans dont know if Michael would have approved or not. Noone in his family say anything in public about the album, so with out Michael, fans are kind of lost about all of this stuff.
8- Social Networks
Why not to use facebook, twitter, and all of these social tools to promote the album? in Facebook maybe some link, some photo, but very random... with a strong campaign they would have reached more people of course.
I am pretty worried about the low sales, really, because the expectations were too high and i absolutly tought Bad 25 would be an amazing hit, that it would be in the first positions of the charts a lot of weeks, but it was totally dissapointing at the end. I do think Sony tried to promote the album a lot, and they did, not in a very smart way but they did, and i am pretty worried about how this will influence the future releases. because of course i am waiting for Dangerous anniversary, and History and postume albums, but fans have to stay together and support any project from now on.