Go back literally 5 posts from when this was posted and you will see some. (In fact, the response directly before this is talking about them)
Have you ever played one of those free to play money sucking mobile games? Their entire grab is that they are addictive but the activities take far too long to allow you to enjoy the game without purchase. What you win from the jump potion is the same. It is instant gratification of having a level 60 character and being top level without working for it. Granted, I have a far greater issue with the levelling potion than the story potion (because the levelling potion is literally paying for experience points on any number of jobs), but both involve you paying to decrease the amount of time it takes to get your reward, just like the free to play mobile games (this is framed from the mindset of someone who is incentivised by the potion)