Boons are one of the trickier elements of the society presented in Vampire. They are the “currency” of the game, the complicated interaction of debts owed and favors given. Given their supernatural abilities, mundane concerns like money are comparatively irrelevant to the Kindred. Instead, it’s the back and forth of favors that defines their relationships, and keeps their society functioning.
In most games I've been involved with, Boon are rare and wondrous things. Almost always they flow from the Elders to the Neonates--young Kindred need something they can not accomplish on their own (such as getting a favored ghoul out of legal trouble, or cover the death of a prominent mortal at their hands), and so they need to approach a more entrenched vampire to do these things. Such favors are rarely given, and then only at great cost to the supplicant.
This makes sense, but really only in the context of a 1st Edition game--specifically one that focuses on the “classic” vampire struggle of anarchs vs. elders. In the original version of the game, the Elders, as a group, had no need for the Neonates. In fact, the Neonates very existence was resented by the Elders, as they represented nothing but a risk and a threat to them. With little resources of their own, these young, foolish and hungry vampires sought to take what the Elders already had, and their very foolishness threatened the existence of the Masquerade. As such, the Elders had no need for them, and would only deign to treat with them under the most unusual and favored of situations.
Thing is, this does not make sense in other versions of the game. Obviously, if the coterie are Archons or the Brood of the Prince this dynamic is altered. But it’s also changed in any situation where raw, naked conflict is more prevalent. This conflict can be pretty much anything--an on-going struggle against the Sabbat, against Lupines, or even a highly balkanized setting where various “houses” of Kindred are constantly at each others throats. Or even one that focuses on the changes of technology and society, and the risks and dangers these present to the Masquerade. Basically, if you have a setting where social and tech savvy neonates have a role to play, or one where stupid, violent, and overly in love with their ability to talk to dogs and leap across rooftops neonates have a “healthy” outlet, then this dynamic of stingy Elders and grasping Neonates doesn't really work.
See, being in Social Debt isn’t a horrible thing. In the books, it’s presented as such, and there’s a lot about avoiding being in debt to another Kindred. But a Neonate being in debt to an Elder can actually be a useful thing, for both parties. Setting aside from now the raw value of the actual favor itself, if a Neonate owes an Elder a favor, that Elder now has a vested interest in that Neonates future. After all, a poor and unconnected Neonate has little to offer the Elder--but, if that Neonate has the potential, in a few years, to gain significant resources and influence, then the Elder can have the repayment of the debt be many times its initial value. Now obviously, a wise Neonate won’t take on too much debt from a single Elder, but being in debt to multiple Elders can provide a critical early base of support. Each of them is vested in your future, and you can expect them to step in of their volition to assist you in the Jyhad, if only to protect their investment.
Conversely, there is value to an Elder to place themselves in debt to a Neonate. Having some “sway” (no matter how minor) over an Elder firmly places a young Kindred in the system, and encourages them to “play ball” and not go Anarch. It also establishes an element of trust between the two, and can be the baseline for a close, personal connection, which is the best way to guide and influence this young Kindred to the Elders profit. And, much as with any debt, it helps make that Neonate interested in the furthering of the Elders schemes, since having a prominent Harpy in your debt is one thing, but how much better would it be if that Harpy became a Keeper of Elysium?
A key part of the game, and the ability to create plots and stories, suffers if the Storyteller is too stingy with Boons. Used properly, they can quickly get the players wrapped up in the Jyhad, and make them players in the game, rather than just people on the sidelines, waiting to for plots to come to them. But there’s also a “game” element too, and Boons can be one of the great “rewards” a player can get.
D&D remains one of the most popular games out there, for a number of reasons. One of these reasons, I believe, is it’s three-tiered system of rewarding players. After going on a quest or completing a dungeon, a player can expect to get Experience Points, Gold/Treasure. and Magic Items. All of these are neat and fun in their own way, and it’s the variety that makes it work. You might get a lot of XP in one session, a lot of GP in another, and a long-desired or just cool Magic Item in a third. I’m ignoring such things as “world knowledge” or “meeting cool NPC’s” or “the fun of role-playing” and the like for this example. These should be part of any game, after all.
Vampire really only has one reward for the players--experience points. And don’t get me wrong, the “point-buy” system of Vampire is a lot more fun and interesting than the level approach of D&D, but it’s only the one thing. I think this is a waste, since it cuts out a lot of things that can be enjoyable and fun for players. By loosening up a bit with Boons, by having NPC’s not only want to place the players in their debt, but also being willing to go into their debt, you open up another method or “reward” and present the players another resource they can “spend” to accomplish what they want.
Obviously, this depends on what kind of game you want. If you want them to hate the Elders and be actively trying to take them down, you want to keep them stingy. If you want a game of bloody action and feats of derring-do, then Boons really won’t play a major role. But, if you want a more socially focused game, where the players need to navigate complicated webs of betrayal and alliances, where mystery and intrigue are more prominent, then you want the players to have a number of Boons, both owed to others and to themselves.