Needham Canvassing Consultants in Ceresco, MI, offers a consulting service to help businesses canvass effectively.
This thread on Contractortalk.com suggests that door-to-door canvassing is truly effective. Similarly, Ford Harding in his Rainmaking book indicates that if you have the stomach for it, cold calling for professional services can be profitable and valid. My role in reporting on these options is not to denigrate them; they work in many cases, just as do intrusive telemarketing calls, and (yes) spam emails. But is this the type of business we really want to run?
I think the business owners who have employees pounding the pavement with door-to-door canvassers would much rather have an environment where the phone rings and clients call, enthusiastically requesting quotes -- without worrying about the price (which might be well above the going rate). This is the stuff of branding, reputation, relationships, and repeat business. It is about authority, leadership, and effective niche marketing.
But I don't want to sit on an ivory tower in judgment. Cold calling and canvassing indeed are effective, done properly.