Robots, noindex but follow

[designasp]

Hi

I was looking at a particular site to check why they have improved in rankings in the last few months. It seems that they have added browse trees to the footer to all possible categories. As an example, let's say they were a clothing site. Their browse pages are: browse by designer, browse by colour, browse by year etc. They have atleast 10 different browse categories.

Each of these browse pages has a load of links using keywords , for example, the browse by color has nearly a 100 links like this:

Designer Red Clothes
Designer Blue Clothes
Designer Black Clothes
...

could be seen as spam if you ask me. But they rank #1 for each of these keyword phrases and even part of the phrases like "red clothes".

I noticed they are using <meta name="robots" content="noindex,follow"> on all their browse pages.

Why is noindex important? Is it somehow helping them to stay safe from penalty due to overuse of keywords? Whatever they're doing, it's working.

TIA