Why I don't do tfp / tfcd

Today I was reminded why I don't do time for prints or cd. Around mid-day I had a mail from a model I had offered to work with. We exchanged a couple of mails and she expressed a readiness, even a desire to be photographed this evening. I phoned her to sort out details and we arranged that I should pick her up at 6.30pm. All very easy simple etc.
So I arranged my day around this and ran the vacuum cleaner around. At 2.30 I get a text asking if we can move it back to 7.30, so I say yes, no problem.
At 3.50 I get a text asking if we could reschedule for a later date ( Not actually cancelling but in fact it turned out several texts later.... cancelling). "I hate to sound unreliable and usually I wouldn't be"
Now eventually she's says she'd prefer to bring a chaperone which doesn't bother me (as those of models who've brought friends, chaperones, drivers, mothers will know) but the chaperone isn't available today. But the Chaperone was't available today when we made the booking either.
Anyway it doesn't matter, at least it's given me a subject for a blog, but I really can't remember the last time I was let down on a shoot where I paid the model; so its back to paid and part paid. My general view is that if a model's not worth paying then she's not worth booking. For those who haven't worked with me I should point out that I am happy to give models copies of the pictures, so I think that I usually do part-paid shoots.