[tptacek]

Who's "pitching" this to a prospect? You make it sound like something you'd put on your website and in your proposals. Your terms are your terms. A client asks, "I think we'd just like you for an hour or two today, so can we just pay for that", and you say "no, sorry".

[sequoia]

You are correct. I guess I was just concerned that declaring that working on a project for any amount of time, no matter how small, precludes work on anything else for the rest of the day sounds a bit too inflexible, bordering on incompetent. Your comments indicate that you are not actually this inflexible with good clients, to the contrary you are generous with small amounts of time, so I'm not sure why you'd want to tell them you are 'unable' to work on more than one project per day ever; it seems like you're selling your abilities short. Basically I agree but I'd phrase it in terms of efficiency and ROI: the value delivered in X amount of time plummets when you have to context switch. Anyway thanks for the sound advice!