The main downside to selecting a free web hosting service is the advertisements and pop-ups that are non stop. Also your URL will have their company name in it,
Free web hosting services allow a lower bandwidth then paid hosts. Sometimes free web hosting sites have been known to change their terms & conditions, or even cancel their free hosts and force you to either pay them or lose your site. The free host controls everything you and your website does, and this isn\'t good.
If you are planning on using your website as a person site for family and friends, then a free web hosting is sufficient. However if you are using your website for business purposes, then it is highly recommended you invest in a paid web hosting service.
There is only one downside to paid hosting, they cost you money. However there are many upsides included in this investment. With paid hosting you host your own domain, so if you change the web hosting service in the future you can easily transfer the domain to your new provider with out any loss of traffic.
Paid hosting services usually offer 24/7 customer support through email, live-chat, or toll-free phone support. With paid hosting you are generally offered enough disk space and bandwidth.