Back in 2008, I was deep into building eBay niche stores using a WordPress plugin called phpBay. These were affiliate sites that displayed eBay listings organized around specific product categories. It was a legitimate business model at the time, and one question kept coming up in the community: could you use trademarked brand names in your domain name or URL?

The conventional wisdom was something called the “third slash rule.” People believed that eBay's terms of service prohibited using any trademark in the portion of your URL before the third forward slash. So “mycarshop.com/bmw” was supposedly fine, but “mybmwshop.com” was not. I believed this myself for a long time. Then I actually read the terms of service carefully.

What the eBay TOS Actually Said

The relevant section of eBay's affiliate terms prohibited using any company name, domain name, or URL that incorporated eBay's own trademarks, trade names, or those of its corporate affiliates. It also prohibited using any generic word followed by “Bay” in a way that could be confused with the eBay brand.

The key distinction that most people missed: the restriction was specifically about eBay-related trademarks, not about third-party brand names in general. eBay did not want you creating sites like “eBayBargainShop.com” or “TechBay.com” because those could be confused with eBay itself. But the terms did not prohibit using a product brand name like BMW in your URL, at least not from eBay's perspective.

Now, BMW's own legal team might have a very different opinion about you using their trademark in your domain name. That is a separate issue entirely, and one that involves trademark law rather than eBay's affiliate agreement.

The Bigger Lesson About Terms of Service

This experience taught me something that applies far beyond eBay. Most people in online business have never actually read the terms of service for the platforms they depend on. They rely on forum posts, blog articles, and secondhand interpretations that may be partially or completely wrong.

When your business depends on a platform, whether that is eBay, Amazon Associates, Google AdSense, YouTube, or any other program, reading and understanding the actual terms is not optional. It is a fundamental business responsibility.

Terms of service change constantly. What was allowed last year may be prohibited today. What was prohibited may now be fine. Set a recurring calendar reminder to review the terms for every platform that generates revenue for your business, at minimum once per quarter.

Community interpretations spread like wildfire. One person misreads a clause, posts about it in a forum, and suddenly an entire community believes something that is not true. Always verify against the primary source.

When in doubt, ask. Most affiliate programs have support teams that will clarify their terms if you ask a specific question. Getting a written response from the program itself is far better than guessing based on a forum thread.

Platform Dependence in 2026

The eBay affiliate niche store model that was popular in 2008 is largely a relic of that era. But the underlying principle of platform dependence is more relevant than ever. Whether you are building on Amazon Associates, running ads through Google, monetizing through YouTube, or selling on Etsy, your business exists at the pleasure of that platform.

Understanding the terms of service is your first line of defense. Diversifying your revenue sources so no single platform can shut you down overnight is your second. Both are essential for any sustainable online business.

Read the terms. Understand the terms. Build your business accordingly.