Because the CEO of BigCo isn't likely to award you a big contract if he gave you two dollars for coffee not five minutes ago. Picking up (advertising) pennies is not without costs.
Your answer made sense. Tim Harford did a piece on why people who refuse to be team players (e.g. take on some extra work that's "beneath" them) end up making more money. I assume you mean a signalling scenario like that.
Hey, sorry I didn't get back to you on this. Really, a response to this question needs to be a blog post that I don't have time to write at the moment, but I've put it on "the list".
