In public, he buys and trades fresh fruits. Most notably, the apples the town gets it's name from are traded under his ledgers.
He often has the best secrets, but is loathe to share them. If you can earn his trust, he will gladly trade information, however. Specifically, Keeto knows who trades what, and that is not information he will trade. Instead, he accepts jobs to facilitate the sale.
Example: The party needs to buy Zupberry Bark for an alchemical item. Keeto knows who sells it, but only agrees to make it happen.
Following him does no good, as a lot of his deals are highly structured to reduce liability. He rarely visits contacts in person, and has drop times set up. One might ask for his assistance, follow him, and learn nothing more than he went home for a good nights' rest. Rest assured, those who do follow him will be noticed, he seems to have a knack, or perhaps spies.
The party should be able to trust Keeto Len. He acts selfishly, and defensively, but does not want any harm to come to Applewood, or it's heroes.
* A fence typically buys items that are less than trustworthy. Stolen goods, illegal items, and risky business matters are in the purview of a fence. In addition to buying these items, they frequently know how to off-load or sell them quickly, quietly, and for a decent profit.
When you need an NPC you don't have time to make one up on the Fly. A good storyteller has between 6 and 7 NPCs on standby that can breathe life into your campaign. Don't worry, Here is a weekly update for you to use!
Bag of Holding