Hi Daniel, This post is so old and yet no one took time to reply to you, that's too bad, very discouraging. I have started groups and have a couple groups now where this is how it goes. Anyways...
I was wondering what you were really trying to get at here, is it for category titles repeating themselves? You never mention what you are concerned with , I assume you are talking about "keyword spamming"? Using a keyword too often? Yet you do say you would be changing the sub-category often, which is what most people would expect in a shopping experience. I mean the nature of the meaning of "category" suggests there are lots of items within that group and that the more it is defined with sub-categories, that is where we learn of more detailed landing pages.
The only time you should change any title is if you realize you can never rank for that particular keyword phrase. or it is too expensive for Ad Words. Never waste space on titles with generalized descriptions you can't make money from, unless that title is the best thing that will get your subcategory titles noticed. Does that make sense?. In other words, your category titles, your subcategory titles and each landing page title should be an opportunity to use keywords that get your company seen, they are keywords that real people are right now typing into their little computers.
I can't imagine a keyword category getting penalized because it is repetitious. If you always follow one simple seo law than you won't go astray. It is as follows: Make sure every word you choose is on point for the final landing page and that the word syntax is a perfect match. If your category is "men's clothing" and one finally lands on a page displaying baby carriages or women's purses, than obviously this is a problem. You can't be seen as an authoritative resource if your page(s) syntax are all convoluted. Its all about making your site as user-friendly as possible, that is it really, even if means a hundred topics within one category, than that is exactly what the URLS should reflect. As long as your URL is human readable and on point, on topic, in relevance, with your URL names than that is a good indication of good content.
With Googles Hummingbird algorithm one really has to make sure the syntax is sharply defined and dead on point. I don't know my friend if that helps though no one else spoke up here. so I tried. Take care-- Roman
On Wednesday, January 28, 2015 at 4:20:02 PM UTC-8, Daniel Marcos wrote: