It looks like a really good idea to add that option in their site but I dont prefer investing money there because everybody can earn more money with paid to click sites and revenue share.
But the FreeBitco.in investment intention is to pay you passive income, what means you are doing nothing, your money is working for you. With a decent balance you will earn much more than what you earn clicking ads on PTC sites or any other thing like this.
It's not possible to compare a passive income investment with a PTC site task/job/hobby.