Being online 24/7/365
The internet never sleeps, and you're sure to have customers, clients, or visitors log in or open up your page at any time of the day. When they do so, the last thing you want is for your site to be down! If it is, that'll lead them to either go elsewhere, or mentally blacklist you as a site not worth spending (wasting, really) the time to visit, because it wasn't there the last time they dropped in on you.
Websites that are always up (and by always, we mean always) and high uptime hosting providers are the ones who outdo everyone else in a key performance area: being up and running, and online, and functioning smoothly, with less downtime than anyone else.
Take your business where it'll be supported

Everyone with a webpage wants their page to be up all the time, so a discussion about who needs high uptime hosting is somewhat unnecessary. Instead, let's talk about how not having your site hosted once it's been launched can seriously damage your website or business, even if the downtime or site compromise is only for a few minutes.
First of all, you are likely to miss out on visits from the potentially thousands of people online at any point in time searching for something related to your line of work. These are potential conversions missed.
Further, you may miss out on a chance lead or a quick sale if someone who was ready to buy or to take the plunge drops in to your site only to find it down for maintenance.
Finally, when we talk about trusted and reliable hosting plans, we don't just mean the plans that never go down for maintenance, but the sites that never crash as well. This means having a hosting provider that not only provides hosting services but one that also vets its clients, knows what's going on with them and their online presence, knows when site overloading (and subsequent crashing) may occur, and knows what to do in such situations to avoid issues for all of its client base.