Hey Jan, glad it made you think. As you've found out it's not easy to rank #1 on Google especially when so few people will link to your product reviews. You need to tackle a specific niche with a focused target audience as a whole and build a community of like minded people around your site in order to make any significant income online sustainably and for the long term.
Selling graphic T-shirts is big business. Customized T-shirts with clever sayings or graphics are ideal for online sales. Sites like Teespring allow you to sell customer shirts. Teespring’s unique model allows you to design the shirt and get buyers lined up to purchase it. This saves you from the initial investment in stock and the time on processing and shipping orders, though you’ll likely make a smaller profit on each shirt sold.