The person who uses a product or service. If you make T-shirts, a person wearing your shirt is the end user. If you make websites, the person who hires you is your client or customer and the person using the website is the end user. Either way, do your best to avoid referring to people as “users” in your marketing materials. It’s accurate but not ideal.
Whether you choose to do your marketing online or offline, one thing does not change. This is the concept that no single marketing strategy will be as effective as a combination of two or more marketing strategies.