Some visual flair, a bit of bold imagery and a beautiful custom font or two can be great ways of making your website enticing. Those elements bring trade offs though in the form of increased page weight and load time.
The great thing about a website is that it can be accessed anywhere, from a bucketload of different devices. It’s also a challenge because you don’t know what context your users are coming from.
Those design enhancements that delight someone in their office could be a source of frustration when your page loads slowly when they’re out and in a hurry. It is possible to detect devices and remove some of the unnecessary, heavier items from the page, but this approach isn’t perfect. An iPhone struggling to hold onto a 3G connection is a different beast from one connected to a good WiFi connection; so knowing what sort of device your user is on is only part of the story.
It’s important to consider everything added to the page as having pros and cons. Being too stingy with the page weight could lead to a boring design. Being too fast and free with image sliders, video and graphics could come back to bite you when a busy user on a bad connection gets frustrated and leaves.
The design needs to balance these needs.