Valuation or Phantom Investor Scam:
The business sends messages asking if you're interested in selling your business. If you want to sell your business, they claim they have buyers who are interested in buying your company. You send a message back stating that you're interested, and they send someone to come out to speak with you. After that, you pay several thousand dollars in advance to have a valuation done to determine what your business is worth. After you've paid, they disappear.