Many service professionals -- everyone from accountants to virtual assistants -- give clients the option to work on a retainer basis, i.e., the client pays a fixed monthly fee to cover a certain level of service. Sometimes this equates into an exact number of hours (usually at a discount, in exchange for the prepayment and commitment). Other times, it's to cover certain work, without having to track it hourly.

This is attractive to the client because they get a discount and have some idea what they're going to spend every month. It's attractive to the consultant because it locks in a guaranteed number of hours. A small number of clients on retainer, and you know you're "covered" financially for the month.

On one of the discussion lists I'm on, a PR consultant asked this question:

I have a new prospective client that wants to buy hourly rates instead of a retainer. What reasons would you give a client why a retainer is better for them and why hourly services are not a good option for them?

Branding guru Rob Frankel, in his imitable style, came back with the perfect answer -- humorous and accurate:

What's the problem? Give him your hourly rate along with the minimum number or hours he has to purchase -- in advance -- every month.