WordNet
n. a fee that is paid to someone who finds a source of financial backing or to someone who brings people together for business purposes; "the agency got a finder's fee when their candidate was hired as the new CEO"
Wikipedia
In the United States, a finder's fee is the compensation given to an intermediary in a business transaction. Usually, there is a causal relationship between the one party and the intermediary (the finder), another relationship between the finder and the second party, and the two parties of the transaction would not have met if it were not for the work of the finder. Such compensation is common in business and is regulated by contractual agreements and law in the United States. A finder's fee can also be a gift from one party of the transaction, who feel morally obligated that the profits of the transaction be shared with the finder for making that transaction possible.
The term is sometimes used in the context of criminal activity; for example, convicted sex offender Jared Fogle reportedly offered a finder's fee to an adult escort if she helped him find underage girls.
Usage examples of "finder's fee".
Cromf's finder's fee, we're not going to break even on this as it is.
That had been the reward Zek had offered for the rescue of Ishka: fifty bars of latinum, which had been split evenly among the six Ferengi who participated in the rescue (after Quark skimmed off a sixteen percent finder's fee, of course).
If you can find Silas, or identify the people who took him, I'll pay a suitable finder's fee.
Split five ways (Kelp would give his nephew Victor a little something as a finder's fee out of his own piece), it left Dortmunder and Kelp and Murch and Chefwick and Bulcher a solid reasonable seventeen thousand dollars each.
Perhaps those who hired them always did so with distaste, washing their hands after passing them the cachet of the slave they were to hunt down, washing again after giving them their Finder's fee.