How quickly a website shall open would depend not only on the Internet connection of the customer, but also on the connectivity of the hosting server where the website is hosted and on the network infrastructure - routers, server network card, etcetera. Slow connection or hardware that can't deal with a high volume of incoming and outgoing traffic could have powerful impact on the consumer experience of your visitors and the functionality of your site because people will probably see error messages that the site is not available or it shall take a long time for your content to load. In case such a thing takes place, it's not likely that the website visitors will revisit the site. Because of this you should always examine the connectivity of any hosting machine that you buy and not only the main hardware components such as hard drive, central processing unit and physical memory.