It would be mostly worth for those who buy popular keywords first as in comparison to those who will try to buy keywords too late in which they will most likely end up with non popular ones therefor they wouldn't be making any significant money. Hope it wouldn't turn to be a scam in the end since many have invested so far ever since the trial phase.
Value of keywords is directly proportionate to how much they earn as the number of users grow and start searching we will discover which keywords a re really valuable for sure. As we now go into app development phase kind and types of app might also determine the usage of keywords. E.g. One of the apps we are working on is food recipe search if people find that interesting certain food related words might get higher searches.
Still only 1162 users and we have not even began are scaled marketing campaign yet, wait for a while before you draw definitive conclusions.