Subdomains are often created in connection with landing pages.
In my opinion, this is a rather dubious method for SEO for the following reason:
The subdomain is treated by Google as a separate domain.
However, one of the many important factors in SEO optimisation is to allow the main page to grow in size. By creating subdomains, the main page loses volume. I therefore advise against this.
It is better to position the landing page in a subfolder. If necessary, the content can be expanded and the website thus receives more volume. In addition, the search engine is not "stressed" with new domains. Keep the page structure clear and simple. This makes it easy for search engines to index your site. If you publish content regularly, you will quickly achieve a good position.
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