A high yield investment program is essentially an investment in which you have the choice of how much you can invest in the program, hoping for a high yield. Any amount can be invested in a HYIP, and in fact small amounts works rather well for HYIPs, but there is an advantage (and disadvantage) to using large investments.
An autosurf is better known as a traffic exchange; a person buys advertising that is placed in rotation with other advertisements. Each advertisement usually lasts less than 30 seconds before it is replaced with another ad. The viewer has the option to click on the ad for more time to look at it. By viewing ads, a person can accrue an income, and some people actually accrue hundreds daily, especially as accounts usually have some kind of compound interest attached to them. To upgrade the account level, money must be invested into the account (making autosurfs an investment opportunity).
Both plans can yield a substantial return depending on time and money invested. HYIPs offer potentially higher yields, but also have higher risks involved. On the other hand, autosurfs offer lower yields and require much more work. Depending on what kind of...