Start with the right question

A thumbnail should help the right viewer decide, ‘This is for me.’ It does not need to attract everyone. For a Mahjong brand, the useful question is not simply whether more people clicked. It is whether the packaging accurately introduced a video they wanted to watch.

YouTube’s impressions click-through rate measures viewing after eligible, registered thumbnail impressions. It does not cover every way someone encounters your video, so dividing total views by impressions will not reproduce the metric. Traffic source and audience also affect the result. YouTube’s CTR guidance, linked below, explains these distinctions.

Give each video one clear promise

Before designing, finish this sentence: ‘After watching, you will understand…’

For a tile comparison, that might be how two tile sizes look and feel on a standard rack. A title such as ‘Large vs. standard Mahjong tiles: a side-by-side comparison’ tells viewers what they will get. ‘These tiles change everything’ does not.

Then let the thumbnail supply visual evidence: both tile sizes, photographed at the same scale, with the differences easy to see. Avoid cramming in the case, accessories, logo, three claims, and a full sentence. Check the design at phone size. Can someone identify the subject without zooming?

Make the opening keep the promise

If the thumbnail shows a size comparison, begin with that comparison—not a long logo animation or an unrelated introduction. Establish the question, show the products, and explain how you will compare them.

A useful thumbnail is a contract, not a separate advertisement. A striking image of an intricate tile back is appropriate when the video explores that design. It becomes misleading when the design barely appears.

Compare like with like

Review videos with similar subjects, formats, and traffic sources over comparable periods. A search-led tutorial and a broad product reveal may reach different audiences. Their CTRs are not a clean design contest.

Avoid reacting to a handful of early impressions. Record the title, thumbnail concept, traffic mix, and viewing behavior before deciding what to change. If you replace a thumbnail manually, treat a later improvement as suggestive rather than proof: the audience may have changed too.

For Shorts-feed performance, use the separate ‘stayed to watch’ measure rather than treating thumbnail CTR as the feed’s watch-or-swipe decision. YouTube’s content analytics guide, linked below, defines that metric.

Choose the next experiment

Identify one plausible weakness: an unclear subject, unreadable text, or a promise that is too broad. Make the next version address that weakness. Review CTR alongside retention and audience relevance. There is no universal target that makes a video successful; the goal is a clearer invitation followed by a satisfying watch.