InfoUSA & Sales Genie and other list brokers offer Free 100 list. You can tailor the list using the list brokers site, to feature company size, number of employees, mailing address, phone number etc. zip code, company president etc.
ThumTack.com sends out commercial cleaning leads for large offices 10,000 sq ft and up. These leads usually are for medical offices, retail and general office space. Thumbtack you pay for the leads you bid on and bidding is limited to 5 bidders.
Brad BD Janitorial