Sorry if this has been posted, but Makai Shin Trillion has a interesting way to encourage people to pre-order the game.
The yellow bar on the left is the amount of pre-orders (updated weekly). As more pre-orders come in, it will grow and gain ranks. Gaining ranks will unlock DLCs and other stuff which will be given out for free. The funny thing is, it also shows whether the game is making a loss or profit based on the current level of pre-orders. Ranks D, C and B are the "loss" levels. Rank A is "recoup ~ profit" level, and finally Rank S is "super profit" level.
Steam has offered a similar system for a while for those who want to use it for preorders but it's pretty rarely utilized.