You cannot be so sure that it is a scam as it is making a payment on regular basis so it would be too early to make a judgement that it is a scam. The people are against it as they are not able to digest the pay out they are making and surely they will say it is a scam but it might prove to be the best campaign in the future if it is genuine as its payout is the maximum.
I haven't invested or looked at any of their investmentment plans but in the scam accusation thread , there is enough proof to show that they have faked a lot of things on their website. I couldn't even find an ANN thread for their investment site, which makes the way they run the site extremely fishy. However as for investments , I have seen a lot of scams making payouts in the start and then stopping after they make enough money, so you would want to be careful where you invest your money.
Yes they will pay for certain period of time to attract the users to join their campaign and they will surely pay for month or two to gain an attention from the users and once they are done with their profits they will simply disappear which would directly affect the investments of the users so it is better to be more careful before joining campaigns.