I really don’t have to tell you, speed and reliability are key when it comes to a hosting provider.
You know it yourself, if a website is too slow to load you quickly lose patience and click away. Your website visitors and customers are exactly the same.
Your hosting needs to be well matched to the number of visitors you’re expecting and the order volume you’re catering for. If your store revenue is in the millions then you’ll need a much larger server to suit.
Sidenote: we use tools.pingdom.com to test website speed. In a perfect world your site should be loading in under 1 second (where the load begins to feel instant). We also use uptimerobot.com to monitor site uptime.