There are multiple reasons. Our script is completely optimized, which reduces huge load on the server, where you do host the website. This means, script can even run on Shared Hosting, and easily process any amount of transactions (which depends how big you make your HYIP).
Also, our system is secured from attacks, like SQLInjections, XSS, etc.
And the main reason, it is very easy to customize, have unique features, and is awesome!