online video course as advertising for self-employed life coach

My wife is self-employed as the personal coach since very beginning of 2021.

In the second half of 2021 she started to scale her business by creating online video course using foreign contractor assistance (video recording, etc.)

Payment for video course is comparable to her total self-employment income for 2021.

 

Is it correct to claim video course payment as an advertising? 

We were also thinking to claim this expense as a startup cost.

But even though it looks like the startup cost for the expansion of her business, it's not the startup for the business as the whole. So what are the best practices for our case?