cold calling

Theoは行方不明の友達April Finnemoreが父親に連れ去られたと睨んで、父親の売れないバンドPlunderを手掛かりに調べています。
So far, there was no sign of Plunder. Working in the Raleigh-Durham-Chapel Hill area, Theo had found dozens of music halls, clubs, private party rooms, concert venues, bars and lounges, even wedding receptions. About half had websites or Facebook pages, and not one had mentioned a band called Plunder. He also found three underground weeklies that listed hundreds of possible venues for live music. Using the office landline, Theo began cold calling, in alphabetical order. The first was a joint called Abbey’s Irish Rose in Durham.
Theoは片っ端から "cold calling" をして手掛かりを掴んだ様です。 "cold calling" はここでは電話ですが、 セールスマンのアポなし訪問の意味で使われていたのを以前何かで読んだことがありますが、ブログに取り上げた記録がないので、辞書で再確認します。
・Cambridge English Dictionary: the activity of calling or visiting a possible customer to try to sell them something without being asked by the customer to do so: We were cold-called by a company offering savings on our phone bill.
・Wikipedia: Cold calling is defined as the solicitation of business from potential customers[1] who have had no prior contact with the salesperson conducting the call.[2] Cold calling is used to attempt to convince potential customers to purchase either the salesperson’s product or service. Cold calling is generally referred to as an over-the-phone process, making it a source of telemarketing, but can also be done in-person by door-to-door salespeople. Though cold calling can be used as a legitimate business tool, scammers can use cold calling as well.