I know someone who doesn't say no.
He won't say 'no, I cannot make it', and he doesn't show up.
She won't say 'no, I don't like it', and she doesn't buy.
He won't say 'it's not a good time', and he keeps you waiting.
She says 'I will do it tomorrow', and when tomorrow comes I cannot reach her. 
When he is being really optimistic he says 'let me finish this first, then I'll get to your request'. And, you guessed it; he never gets to your request.
She is very affable, so you keep asking, hoping this time around she really will pitch.
He is very social, so you know he is not a bad guy. Still when the chips are down, he is not the one you will count on.
I know something else about this person. She is always busy, yet she cannot pin point the results of her 'busy-ness'. He is tired a lot of the time, yet he doesn't have time to stop and rest, 'so much to do'. There's always something happening in her life. She always has plans. He is running around a lot, cutting deals here and there, and he has nothing to show for all that effort.
She has lots of friends, but when push comes to shove, she has no one to lean on.
He is a popular guy, but no one wants him leading their committee.
Has anyone been whispering that 'you are all talk and no action?' Do you want to be different?
How about starting by taking stock of exactly what it is you spend your day doing. Whatever your profession or business, take some time to record what you do every hour of the day.
Then write down what you achieve doing what you do every hour of the day.
What do you notice?