Some letters are more common in business domain names due to a variety of reasons. Here are some factors that may contribute to the popularity of certain letters in business domain names:

Memorability: Certain letters are more memorable than others, making them popular choices for business domain names. For example, vowels such as “a” and “e” are often used in domain names because they are easy to remember and type.

Brandability: Some letters are more brandable than others, making them popular choices for businesses looking to establish a strong brand identity. For example, letters such as “x” and “z” can help convey a sense of innovation and modernity, while letters such as “k” and “q” can suggest a sense of strength and power.

Availability: The availability of domain names can also influence the popularity of certain letters. For example, if a certain letter combination is already in use, businesses may choose to use a different letter combination to ensure that their domain name is unique.

Spelling: The spelling of certain words may also influence the popularity of certain letters in business domain names. For example, words that are commonly misspelled may be more likely to use alternate spellings or letter combinations in their domain names.

Overall, the popularity of certain letters in business domain names can be influenced by a variety of factors, including memorability, brandability, availability, and spelling. By selecting a domain name that is both memorable and relevant to your brand and industry, you can help establish a strong online presence and build a loyal customer base over time.