There is a company in India that does something similar, but they do it manually. They call their people “research analysts” and pay them around $130–$150 per month. They mainly use Google Techniques and LinkedIn/Sales navigation to find information about companies and the people who work there. Their services include:

1. List building – finding targeted job titles with their contact information.

2. List research – finding contact and company details of given people.

3. List verification – manually checking if the data is correct, sometimes even calling the contact person to confirm.

Apollo is a big competitor for their 'B2B leads(*dataset)' business because it is much cheaper. A tool like this could have a huge impact on their business.

Curious: Have you compared it with manual research? How accurate is it?