Those are great points, but the question becomes a matter of the stage of the company. Clearly, the author still benefits from making cold calls, whereas in most cases, this starts out as a reality but becomes less and less as the company grows.

Also, we know our ebook is a potent conversion tool. I think it stills comes down to the question of industry marketing practices: we've found inbound marketing to be much more effective because of the saturation in cold calling.