It is generally pretty ineffective and a waste of your time or resources. Example cover letters are kind of like shoes.
While this example demonstrates the information you need to include in the section, there are various ways to format it. After that, it really pays to address the letter to a specific person.
And if you spent your time being unemployed trying to better yourself for example, taking a class or volunteeringthen shift the focus to that.
This will only increase your chances of securing that coveted interview. Be wary of spending hours on perfecting your CV at the expense of your cover letter.
Standard, conservative style This is ideal for sectors such as business, law, accountancy and retail.