I think it is important for domain name owners who park their domain names to be sure they are not infringing on another company’s trademarks with their pay per click advertising links. I like to set specific keywords (using the Specific Keyword checkbox) at Uniregistry to avoid infringing on other marks.
One of the great things about dictionary .com domain names is that they are generic enough that they can be used by a variety of businesses. A brand like Apple is used as a technology company, but of course there are many brands with “Apple” in them that are related to the fruit. If I owned a domain name with the word “apple” in it, I would park my domain name with a specific keyword to avoid infringing on the technology company’s trademarks.
I do almost all of my domain parking at Uniregistry these days. As you likely know, the company no longer shows imagery on the landing pages when visitors arrive on a desktop browser. Using my “apple” example, in the past (or with some other parking companies that use images), the lander could have pictures of the fruit or fruit trees to illustrate that the page isn’t targeting the technology company. If there was one rogue link for watches or something, the domain owner could argue that the imagery shows the intent wasn’t to infringe on technology marks. Without this imagery, it would be more difficult to at least show there was no intention of infringement.
When I park a domain name that another company could theoretically claim is part of their trademark(s), I visit the landing page and check the keyword. Parking company algorithms are built to generate the most revenue for the domain owner, and I don’t think they pay much attention to the sometimes grey area of intellectual property. The onus is on the domain owner to make sure their parked names are not infringing on another company’s IP.
Setting specific keywords is important in keeping valuable domain name assets safe. I would hate to be challenged on a five figure domain name because it was monetized in a way that made a couple extra dollars in parking revenue a year.