Back when I was talking with other people about a Star Trek MMORPG, various suggestions were made for how to rewards to associate with promotions in Starfleet rank.
One suggestions was to increase the size of the player's personal inventory when they gain a rank. Another was to give players bigger "hangers" for more personal ships.
The more I think about these ideas, the less comfortable I feel with the idea of giving only positive rewards for increasing rank. It seems to me that making higher rank always and clearly better than lower rank just creates the same "gotta level up!" mentality that makes other games so exhausting (i.e., not much fun to play).
Why should increasing rank be better? Why should lower ranks be less fun? Why not distinguish the different ranks by making them different in their gameplay, rather than just cranking out the usual "more of the same, only more so" gameplay design?
It's just my vision for Star Trek Online, but I'd much rather that players didn't feel forced to "level up" in rank. If I enjoy being a Lieutenant (because of the gameplay typically generated for players at that rank), why should I feel like I'm being penalized for not spending all my time grinding missions for prestige I can use to buy higher rank?
What if increasing in rank wasn't just about gaining more advantages, but also meant that you're expected to spend more time insuring that other players are having fun? Isn't that an appropriate expectation in return for higher rank?
As an example of this, maybe dinging to Commander means you get more inventory space and more room in your personal hangar, but your newly-elevated status also brings with it the responsibility of writing mission plans and staff evaluation reports. Maybe getting bonus prestige points as a Commander means insuring that the functionality status of each of your ship's primary systems remains above 95% for 80% of your time in space, or that everyone on your away mission makes it back in one piece, and so on.
The point is that making advanced rank mean more than scoring a bunch of purely positive rewards gives players an interesting choice to make. If the choice is between being a great Lieutenant Commander or a good Commander, that's a lot more interesting than feeling that something must be wrong with you if you're too "lazy" to become an Admiral as the conventional MMORPG design would insist.
It's worth noting that the word "rank" is usually short for "service rank." And that says something important about what rank is for.
If rank in a Star Trek MMORPG isn't defined in terms of service to and increased responsibility for others, then something very useful (in a gameplay sense) about the idea of rank may be lost. As a missed opportunity to carve out new territory in the "undiscovered country" of MMORPGs, that would be a shame.