I started a website to promote products (affiliate). I am now asked to submit a W-9. I am not sure that to put as selection. Which would be the best option? Since I am not fully an owner of a business for which I sell products, but people buying others, should I count as partnership?
If you do not have a business with its own EIN, you put your own Social Security Number and indicate individual.
Individual/Sole Proprietor.
You would only be a partnership if you were running your business with a partner. You are not, so you are an Individual/Sole Proprietor.
you are a sole proprietor and report this income on sch C and Se with your 1040