Better for SEO to have direct link to file, or have Action instead which would return FileResult?

I have a couple of PDF files with services descriptions in the URL:

{service_name}_{year}.pdf

I am just wondering what开发者_C百科 would be better for search engines - to index the file with a direct link like http://mysite.com/pdf/service_name_details_2010.pdf(opens in new browser tab using target="_blank" attribute on href) or have action http://mysite.com/pdf/servicename/2010 which would ask user to save the file.

So what is the better way for SEO, what would a search engine crawler prefer more?

target=_blank can easily be over-ridden, and is a hasn't been a supported attribute for some time. I'd suggest you read the following: http://www.useit.com/alertbox/open_new_windows.html

With regards to SEO, the search engines will identify the documents for what they are regardless of the file extension: http://googlewebmastercentral.blogspot.com/2011/09/pdfs-in-google-search-results.html