Vector design is the perfect way to jazz up a bland or simplistic layout. Nowadays designers can export SVG icons which naturally expand or animate for unique visual effects. Connecting a branded vector character into your company logo is a memorable way to capture attention. It certainly works for these websites!
Below you can find a number of excellent vector-based icons blended into typical website layouts. This is a solid collection of websites to understand how other designers create these effects. You might try designing your own Illustrator vectors for the web and see how they can improve overall visitor interactivity.