Ensuring your hosting setup is correct for your site is vital as it can have many factors upon performance and user experience. For example if your site needs caching so cpu usage is reduced and dynamic content is shown quicker then only some hosts may be able to offer this to you. If your site is expecting a high amount of visitors/hits then you should ensure your hosting has enough memory and bandwidth to allow for this traffic to get the information it is requesting without going over it's limits. There are different costs and types of servers such as shared and VPS, dependant on the size of your site this may differ but most start up bloggers only need shared hosting.