This answer is based on a question posed to me on Quora.

I’ve only used finder’s fees sparingly over the course of my professional services career. Here are some reasons why:

1. Some of the best referrals for me have come from other people that currently work either for the client or as a consultant to the client. Providing a referral fee can sometimes create a conflict for those parties providing a referral. The same applies to me providing referrals.
2. Other referrals come through people that know me or know of me. In these cases, I may provide a referral fee (or something else) more as a unwritten gesture than as a contractual, business regularity, mainly since business through these channels is very much appreciated but more irregular.
3. Unless designed properly, the referral fee can be stranded between a space where not enough incentive is provided (or even insulting to the referrer), too much incentive is provided and margins are decreased too much, and/or an unwritten obligation is created where the referrer feels overly responsible as to whether the referred is successful or not (as opposed to being arms length from both the referred and the client).

Others may have different experiences, so make sure to get some other perspectives.