Phone call leads needed in different niches

I am looking to hire contractors that that have experience in phone call leads to provide me valid phone call leads in different niches, one niche per contract. A contract consists of at least 200 valid leads. All leads must be unique and must come from the United States only. You must be able to track your leads counts. Your payment depends on the niche you are working on and is usually between $50 and $100 per contract of at least 200 valid leads. I will escrow half of the bid amount when I award you the contract and will release it when you give me at least 100 valid leads and escrow the other half. I will balance your payment when you give total of 200 valid leads. After completing any contract, you can continue the same contract for another 200 leads or start another one in different niche.