I think I have more experience than many in gendered toy marketing. I used to work at Kmart, and the one section of the store that needed the most attention during the holiday season was the toy department. That entire section is a happy little mess of children and playthings. It was a tedious task, straightening up, but we would pass the time by studying (and sometimes playing with) the toys.

Walking through the toy department in almost any store and you'll notice right away how they divide things up between the genders. The boy aisle is usually rather dark looking, with some bold highlights of red and blue. If you're not paying close attention, it looks a lot like any of the unisex aisles. The girl aisle, on the other hand, is very difficult to miss. I hope you like pink, because that's all you'll find down here! I find this sad, because to me, it seems to be sending the children a definite message: boy toys are not that different from average toys, but girl toys are a whole world of their own.
I thought it would be interesting to look up specific toys online, to see what the most popular ones are for boys, girls, and unisex.
Toys R Us has a “top sellers” category, listing the top five toys as the game Mad Gab, the book Goodnight Moon, Fisher-Price Rainforest Melodies and Delights infant play area, Lamaze Buzz the Bug plush infant toy, and Sizzlin Cool Ball Pit Balls. No surprise, these are all unisex, as they have the combined buying power of both genders behind them. In fact, I can't see a section just for boys or girls anywhere on the main menu. Of the top 50 toys sold on this site, Little Tykes Easy-Score Basketball (with a black boy in the photo) comes in first at #10, Nerf sports balls follows at #25, and Tonka Lights and Sound Fire Engine is #40; there are no girl toys.
Amazon does have girl and boy sections. Interestingly, they have separate categories for dolls and action figures, apart from boy and girl toys. At first I thought that perhaps this was a way to show that dolls aren't necessarily girl toys, and action figures aren't just for boys. This is not the case. The
girl page and the
doll page both look amazingly pink and nearly identical. They both are full of role-play toys emphasizing taking care of a home and a family. The
boy page and the
action figure page page are both heavily masculinized. They send the message that boys should be tough and active outdoors. To further emphasize the difference between boy and girl toys, they list sub-categories on those two pages. Girls toys include arts and crafts (a pastel beaded jewelry set is shown), games (Disney Princess game), and dress-up (hot-pink Superwoman outfit). Boys toys include construction (Lego pirates), electronic toys (hand-held Mario), and bikes and skates (bold red Big-wheel).
If masculine toys are tough and active, and feminine toys are domestic and nurturing, then what do we see as being unisex traits for children? Back to Toys R Us top items list, it seems that books are a huge seller. This is encouraging to me, because it frames reading as a human trait, not a gendered one. The other big unisex seller is infant play areas, a small nod to the fact that babies can't comprehend gender differences yet.
Amazon top toys list is full of Zhu-Zhu pets and card/board games. The first is a passing fad, but games are a constant seller in the toy department. In all my experience, I have rarely seen a gendered game. They are marketed on the reputation of bringing families together and entertaining in a way that hopefully won't fade with long-term use.

After seeing how toys are marketed differently to different genders, I now wonder why they are. After all, the top selling toys aren't the gendered ones, they're unisex. And even if they are marketed as gendered or unisex, that doesn't necessarily indicate how the child will play with it. My brother and I would play with Barbie and J.I. Joe together; they would make house and go on extreme rescue missions both. Even the Matchbox Cars would play house sometimes! Perhaps this is one of those situations where things are done this way simply because that's how they've been done in the past, and nobody has yet seen a reason to change it.