Scroll effects, 3D models, animated diagrams and clickable explorers can make a website memorable. They can also be decoration that slows the page and hides the information people came for. The difference is usually whether the interaction helps someone understand something.
A useful test is to ask what someone would miss if the interaction were replaced with a paragraph and a picture. If the answer is nothing, the paragraph is cheaper and faster.
Start with what is hard to explain
Look for the ideas that take the most words and still confuse people: how a product fits together, how a price changes with options, how a process unfolds over time, how two choices compare. Those are the candidates for interaction. Things a sentence can explain are better left as sentences.
Talk to the sales or support team about which explanations take longest in conversation. The same ideas are usually the ones visitors struggle with on the site.
Let people change something
The strongest interactive pieces let people adjust an input and see the result: move a slider and watch the cost change, rotate a product to see the side that matters, switch between before and after. That direct link between action and outcome is what makes the idea stick.
Keep the controls few. One or two things to change, with a clear result, are easier to grasp than a panel of options.
Keep the plain version close
Some visitors will not use the interactive part: they are on a slow connection, using a screen reader, or simply in a hurry. The key information should also be available as text, a table or a static image nearby. The interaction adds understanding; it should not be the only way in.
The plain version also helps search engines, which read text more reliably than content drawn inside an interactive scene. It gives a fallback, too, if the interactive part fails to load.
Measure whether it was used
After launch, check whether people actually interact with the piece and whether they go on to do what the page was for. An experience that few people touch, or that sends them away from the next step, needs rethinking however good it looks.
Decide in advance what counts as success. A piece meant to reduce support questions should be judged on the questions, not on how long people play with it.
