I only have anecdotal evidence but I helped a colleague use this successfully. Sourcing companies to email on angelist then using google/linkedin to find contact info of the appropriate person instead of going through the career page. Cold emailed 5 companies and was able to initiate conversations with 3 without sending a resume. The 3 showed interest but after the conversations he only wanted to follow up with 1 and was able to tailor the resume very specifically. Lead to an offer.