Free Hosting Providers are Good for :-

1) Prices : as you have to pay nothing to host/ test your web projects.

2) No grate experience needed to use the services : If you are a newbie in web development or just trying out your intelligence in programming, you will get free codes, templeates for your use.

3) Free Subdomains : you don't need to spend money to buy domains, as you will get enough free subdomains to test your projects. However, they allow level one domain hosting too.

4) They offer enough space and resources to host : One can get enough space to host his project.

But if you are seriously looking at your online business through your website, then you should get a PAID Hosting because not only they provide you serious service, but have liability for any data lose.