Linkedin for direct sourcing?

Many of us do direct sourcing with letters, emails and cold calls. But I'm curious if anyone has tried linkedin to find willing sellers? My impression is that Linkedin is becoming increasingly effective for marketing purposes. More and more business owners nowadays have a personal linkedin profile. Personally, I occasionally get contact requests from other people who are offering their services. But I wonder if such a process can be automated and whether the costs of reaching out to potentially thousands of business owners fall within the budget of a search fund. I'm also curious if the response rate is better than the traditional letters or emails. I'm keen to learn from your experiences :-)