Hi,
I will try to give you a sensible reply based on my own experiences of buying and trying, quite a few Robot EA's!
The site you showed the link to, works on affiliated commisions. So any Robot you buy directly through the 'mother' site earns the site operator/owner a percentage of the Robot cost (usually 50% or 75%). So if you publish a website and 'review' a certain number of Robots saying that this one is better than that one etc. whilst not forgetting to say that certain ones are scams (just to sound plausible), then certain people over the world believe this, and buy the Robot. Some work for a short while (until market conditions change) others do not really work at all, but look good when you see a chart after the event! This selling of Robots generates a lot of money but not through trading Forex!
Just imagine you had a way of making money automatically using a computer. Would you sell it to someone else for $99.00, or would you keep it to yourself and just pocket the profits.