Web host is not an important part of seo but it may affect you seriously. You should be very careful in choosing the webhost. One of my friend bought a webhost through ebay by giving a penny of $10 for a year. It was a good prize, but he was not aware of the consequences that may come. The webhost demand a 99.9% uptime but most of the days it will go down. There is only one person whom you can contact, it is the one who have the web space. But when you contact him he is not responsible to help you because he got nice feetback in ebay and the sail is over. He is no more responsible. If you did not backup the website regularly it will result in the data loss.
There is no one you can contact when you have got a problem and need help on your host. We do not have any guarantee on the data that we upload. It may be lost after the update of the server and it happened in my friend’s case.
If you are serious about a website then you should choose a better webhost that have got some reputation and feedback.
Never register a domain from the host because if you wanna shift from that host in future, you will be in trouble.