In my industry advertising is indeed a key way in which office designers find out about new products.

One form of advertising which is commonly utilized is a yearly trade show where manufacturers rent showroom space to show off their products to prospective buyers. This model makes sense because it gets 60,000 people with purchasing power into the same building to see what products are new and what the latest design ideas are. There is no hidden agenda here and everyone knows what is going on.

This is the same basic concept as a magazine or website advertisement where you try to get a bunch of likeminded people in one industry with purchasing power to subscribe and read the magazine or website. The advertisements (paper showrooms space) are used to show cool pictures of new products companies are selling and now one is fooled by that.

In this industry, manufacturers have brand recognition and a reputation so seeing an ad for a new office chair by X company is an effective way to announce to people who already know of and like your brand that you have a new product.

Hacker News leverages its niche audience to 'advertise' job listings for Y Combinator funded companies. I could probably find out about those jobs elsewhere if I were currently looking for a job, but I'm willing to trade seeing them for using this site. I expect many other people don't mind advertising when it is tastefully done and on-topic with the website or magazine they read or are subscribed to.

Personally, I had never heard of Kiehls, Spanx, Lululemon, Zara, Jiffy muffin mix, or NO-AD sunscreen. However, I don't know if advertising would help me remember these brands better, as I don't buy their class of products often.