I think the category can matter if you're trying to stand out in that category as one of the top projects in the marketplace, like Design. In terms of smaller categories, I think it comes down to the psychology of the backers. The type of person looking at small batch is going to be different than vegan. Honestly, I don't know that market, but that's something to consider.
Overall, I haven't found the subcategories to be a huge role in the project, but that's just my aggregate experience. You can use the ranking though as a selling point.
For example, let's say you're the top in the vegan category, but you're not getting any pledges as a result of being the top in that category.
You can still use that as a "social proof" component to say, "We're #1 in the vegan category out of X projects!!!"
The announcement of that fact might drive more interest than actually being there. A subtle art haha.
It's kind of how like being a bestselling author might not make you much money, but the status can gain attention and credibility, which can then make you a lot of money in other ways.
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