Pro:
Unlike advertising, mailshots, trade shows, etc, cold calling is the ONLY form of marketing that guarantees you a two-way conversation with target prospects YOU choose to go after.
Con:
Unless you do it right, that two-way conversation might only get you as far as "we're not interested" <click-brrrrrr>. And it's difficult, especially if it's not something you do on a regular basis. So you need a strong approach.
Mike