1. Some consumables can be cut into vertical versions to make more pieces, but horizontal versions may not be easy to cut.

2. Most wedding photo design templates are vertical. It is very likely that they spent some money to buy horizontal templates.

3. It may require more effort in the design concept.

4. Things that are new and different are always more expensive, and things are more valuable when they are rare.

5. If you think it is not cost-effective, you can choose the vertical version. If you want to choose the horizontal version now, it means that it is different in your mind. This is called differentiated marketing.