This seems like a good idea to me!
Let's say I run a product transport business. I am hired by a market to deliver purchased items to one of their customers. The market has a good reputation for paying its employees, and I have a good reputation for delivery. If a system such as this existed, we both have the added benefit of being able to verify that the terms of the contract were met.
If I make a mistake, such as forgetting to deliver a portion of the merchandise, the market can see that and remind me. Once I finish the delivery, I can get paid.
So, I finish the delivery, and the customer I delivered to has some goods of his own he wants to transport back to the market. Let's face it, nobody is going to know the names of ALL the reputable companies for EVERY type of job. (Builders, miners, pilots, transporters, etc.) This is the first purchase that he has had delivered, and has never had any reason to look into reputable transporters. At this point, he has to decide whether or not to trust me with the job based solely on the fact that the market trusted me with theirs.
I am not saying this is a bad thing, since it encourages markets and transporters to choose each other wisely, as hiring/working for someone with a bad reputation could cost you jobs or even harm your own good name.
But... since he has access to a system that allows him to check on whether or not I completed the contract, he feels comfortable enough to hire me based on the market's reputation.
I do think that a mechanic that establishes penalties for failing to complete a contract, or keeps track of the number of successful contracts might push the boundaries of reputation-based decision making. It could also penalize unavoidable failures to complete a contract. ( computer crashed, ship destroyed, etc.)