If you're serious about this marketing, get your own VPS (that ALLOWS proxies) and build your own proxy server. I first started with Dante but wanted more than one IP so I put the job to bid and hired a guy that set up my VPS as a proxy server and now I have all the IPs I need and don't need to worry about blocked ports, burned IPs, slow IPs or any of the other problems that go along with buying IPs. My investment? $15.98 a month for 9 fresh IPs with all ports open, secured and under my control. I gave the coder $50 to set it up for me so I have HTTP and SOCKS5 on each IP with PAM control and it works perfectly. I can add as many IPs as I want for $1 each and my host breaks up the C blocks for me. With my 9 IPs I currently have 3 different C Blocks. Takes me only a minute to add more and make them proxies. That is what I think is the best solution for fresh, steady and fast proxies. Of course it depends greatly on what you're doing with proxies if this is the best approach for you.