I run an eCommerce website and I have been thinking about adding PDF downloads to my product pages. These manuals and product sheets are typically hosted by the product manufacturer, though not all resources are safely linkable, since some URLs can often change. In order to avoid possible 404s, I was planning to write a simple link checker, a quick curl request to check if the result is still a
200 OK code.
If a non 200 code were detected, I could fall back to the locally hosted version, so I would still be providing my users with the information they need, while at the same time, I would only be hosting duplicate content if the original location was unavailable.
Now, is this a good idea? I suspect that hosting a file that exists elsewhere could do more harm than good. I am very interested in helping my SEO, rather than hurting it, so I am trying to plan every step I take in advance.