Two of my favorite features:
* Logo Themes: The USPTO does offer the capability to search logos on their site but it's a bit cumbersome. Here's an article about how one can do so. But Trademarkia's interface is much easier & really, it's just neat to browse through logos.
* Trademark Categories: aka Goods/Services Each classification is accounted for here & each has it's own snazzy design leading you into the International Classification. Once you're in a class, you can then look at Federal trademarks alphabetically.
Now it should be said that while Trademarkia is super snazzy, very easy to use & just overall cool looking -- this is a search of the Federal trademarks ONLY, meaning we're missing State trademarks & Common-Law databases.
Also another thing I noticed is in conducting my SAM test, the engine seems to work pretty similar to the USPTO, which means the user will need to be sure to check all possible variations of the mark when conducting this preliminary search.
USPTO Flaw #1, Sound: Trademarkia, like the USPTO, brings up 3 marks for IShine but not Ice Shine.
USPTO Flaw #2, Appearance: Again, same results as the USPTO - Trucool but not Turcool
USPTO Flaw #3, Meaning: This one was a bit odd as Trademarkia resulted in only 1 hit whereas the USPTO comes up with 23. Not sure what happened there.
Even given the above, I still strongly recommend folks use Trademarkia as a preliminary clearance Federal trademark search engine. It's far & above easier to use than the USPTO. Then once your mark clears that preliminary step, you can move on to the comprehensive part of the trademark process.