In Kobold Quarterly #1, Wolfgang Baur talked about giving special non-monetary rewards to characters. One of the rewards discussed are permanent skill gains, and about that he said:
"Skills are the trickiest of all, because the value of skill ranks as treasure really varies among classes. Giving a rogue some skills isn't a big deal. Extra skill ranks for a barbarian or a sorcerer are more likely to be appreciated. I don't recommend giving skill ranks in the core skills of your campaign, the ones that players invest in because they know that Spot or Heal or Gather Information will be useful in many adventures. Instead, I recommend giving ranks in skills that you know will be useful in a few special cases, skills such as Knowledge (Local), Profession (Miner), or Use Rope."
"Skills are the trickiest of all, because the value of skill ranks as treasure really varies among classes. Giving a rogue some skills isn't a big deal. Extra skill ranks for a barbarian or a sorcerer are more likely to be appreciated. I don't recommend giving skill ranks in the core skills of your campaign, the ones that players invest in because they know that Spot or Heal or Gather Information will be useful in many adventures. Instead, I recommend giving ranks in skills that you know will be useful in a few special cases, skills such as Knowledge (Local), Profession (Miner), or Use Rope."
