In my opinion, cold calling is a dead strategy. It probably worked once, but not now, it is only good for getting people annoyed. Emailing, meanwhile, is dying as well, in my opinion. May be it is a better idea to reach potential customers by messengers, if possible. It's faster and more noticeable than email, but not so obtrusive as calling. Try Linked In also.
cold calling has become a past trend in many businesses. Some may be still doing it but with a negligible responce . It is much used even now in insurance business, but people do not like even those calls and they simpley put them off.