It is simple: you need generate income to make your site online. You need pay for the server and pay for the bandwidth. Although the price of a dedicated server is not high, you still have to earn more than $100-200/month for each server to make your site alive.
Most web proxy webmasters use third-party ad services. Some ad providers are good, some do not allow web proxy, and some may run away after a few months. In this tutorial, I will introduce you a few reputable (for web proxy sites) ad providers.
1. Google Adsense. Google is the leader of online ad industry currently. According to its description: Because the ads are related to what your visitors are looking for on your site or matched to the characteristics and interests of the visitors your content attracts, you’ll finally have a way to both monetize and enhance your content pages. If you have a lot of Asian or middle east traffic, this may be the best for you. Google pays you on net-30, monthly. (with minimum $100, if your account has less than $100, your balance will be rolled to next month).
But keep in mind, you can only put Google adsense ads on your main page, because the proxified page is NOT considered as your contents. If you put the ads on the proxified page, your account will be very likely terminated and you will get nothing. So, this is important for web proxy webmasters.
Then, how can you monetize from the proxified pages? The answer is AdBrite.
2. Adbrite. AdBriteis actually an ad market, where you can sell your ad space or buy ads. You can choose to show network ads when your ad space is not sold. Adbrite pays you on net-60 bases. The CPM maybe not so good if you have only Asian and African traffics.
3. Paypopup. Paypopup is a reliable popup and pop-under ad provider. Actually, it is in the same big family of Clicksor. You can choose pop-up or pop-under; I would recommend pop-under and once per session so that it will not affect your visitors.
Of course, there are a few others, but some are not friendly to web proxy sites, e.g., RightMedia. Anyway, as a start, you may try to put Google adsense on the home page, and put Adbrite on the proxified page, as well as the home page. Pop-under usually put on the proxified page only.