There are basicially 2 types of proxy web owners, they are either those who create a lot of proxies and earn the profit by leaving it there or those who creates good proxy and do a lot of advertising and sell it at a high price after a period of time. I will not say which one is better as there are both pros and cons to both methods.
As to answer that question, my personal take will be when you are able to tackle 3 main parts of the world for your proxy, you are ready to sell it. I divide the world map into 3 main parts.
- Middle East
You could always sign up an Google Analytics account and use their Geo Map Overlay feature. If you see “dots” in mainly the China, Middle East, US area. You are basicially ready to sell it.
The reasons are simple. China and Middle East tends to bring in a lot of traffic (beware!) for your proxy and you can earn quite an amount from them. I don’t deny that the PPC are below $0.10 for them but high traffic and high clicks still give you the amount you need. Basicially, we are going for quantity here. US’s traffic tends to give you a much higher PPC and those are the quailty traffic. Most of the time, for me, the amount I earnt from China and Middle East traffic will cover the server costs and amount I earnt from US’s traffic will be my bonus. Exhauste the amount you can earn from the proxy first for the first level and sell it right away for the next owner to bring it to a higher level.
Have fun with proxy.