Mike Monteiro frequently rails against spec work in his show, Let’s Make Mistakes. In a recent episode, he invited venture capitalist Chris Sacca whereupon they agreed that designers aren’t “hustling” enough. Monteiro and Sacca defined “hustling” as offering unsolicited design work as a means of obtaining further work. The difference, they continued, was that “spec work” is solicited and “hustling” is not. The NO!SPEC campaign hints at a similar distinction but not clearly. Is unsolicited design a form of spec work?
I would say that's spec work by any definition. It's definitely "speculative," and there's nothing whatsoever to prevent the recipient from saying "Thanks" and using it without further compensation to you unless you hedge it with Non-Disclosure and copyright legalities (which you'd definitely want to check with a lawyer, and even then isn't bulletproof).
What you CAN do, if you see a potential client taking careful aim at their own feet with a 44 Magnum, is offer a short critique of their existing logo/flyer/brochure/ad with the reasons why it is ineffective. You have to do this diplomatically, of course, and with lavish praise for the bits they got right if it was done in-house or by the owner's favorite nephew, but you can indicate how professional design (or your particular style) might benefit their reach into their target market. This is an approach that has landed me some very loyal clients.
You won't win them all this way, but if you are clearly interested and helpful in your approach, it will gain you business. Clients need to know you're on their side, especially in the initial approach, and this is a good way to do it. The ones who'll reject this approach out of hand are invariably trouble, and as a freelancer you're better off without them.