What does this method do?

A website has started several additional domains that are all keywords. They have then made one page websites for these keywords that are exact duplicates of the pages on their main site that they want to do well on those keywords. The links/navigation on the keyword name web sites all work normally, linking back to the main web site.

When I research back-links for their main site, these keyword one page sites all show up as valuable back links.

Does this method actually help? The master site DOES rank well for the keywords.

I should note that some of these "keyword" sites have been up for a few years.

I think this might work short-term, but long-term there is a good chance that Google would ban him for duplicate content.

I agree with above poster. This would not work long term. Big G will catch on and pretty quick too with the way they have been doing things lately.

Duplicate content and then will face a penalty or ban. In the start they might get some traffic and some rankings but that will only be short termed.

thanks for the replies. I am guessing it was an older method that they tried thinking it might work