In FFXI, Fame will give you lots of possibilities that are out of your imagination. Some quests are only available for high level of fame and you can complete these quests as your fame increases. Many NPCs have multiple quests which they give out in a certain order. These later quests often provide more substantial rewards than the early ones.
In FFXI, if you want your bank account increase, you’d better do quests. The FFXI Gil will reward you directly and the quest rewards can be put into the market also. You can sell the one you don’t need but necessary for others. Quests also break up the monotony of leveling and provide information about the world of Vana'diel. Taking off time from gaining levels to do quests is a fun way to see more of the game.
The NPCs will react differently to you, and tend to treat you a bit better than before as your fame raises. The biggest change is the items at the merchants turn to be cheaper for you as your fame level increases. The higher your fame, the lower the price of goods when you buy from a merchant who is related to that group of fame, and the more a merchant will pay when you sell goods. One thing you should notice is you can increase your fame beyond level 9. It will not provide a new fame message. However, it will be reflected in further benefits when buying or selling at merchants.