Put links in the pdfs.  Edit their "properties" to optimize them for the SERPs.  You can place "buy buttons" in pdfs, include ads in them.  Track the number of views through log analytics.

Search here and here to get lots more information about using pdfs.

If they add the to the head of their page then here is what will happen.....

• the page with your article on their website will not be indexed by Google (they are not 100% good on this but they don't do badly)
• the page on their website will appear in your search console as a link with the note.... "Links to your site" as.... "via this intermediate link:  http://theirdomain.com/page-where-your-article-is-published.html")
• any page on their website that links to your article page on their website will appear in your search console as a link with the note.... "Links to your site" as.... "via this intermediate link:  http://theirdomain.com/page-where-your-article-is-published.html")
• any page on any other website that links to your article page on their website will appear in your search console as a link with the note.... "Links to your site" as.... "via this intermediate link:  http://theirdomain.com/page-where-your-article-is-published.html")

This is how Google currently handles this.  They will likely handle it the same in the future, but they could change their mind without tellin' anybody, which they have been known to do.

In my opinion, this is the proper way of giving your content to other people.  It prevents them from competing against you in the SERPs with your content on their website.  The problem is getting people to agree to it and a lot of other webmasters doing understand it.

This article can be viewed on their website by thousands of people and they can enjoy the ad revenue from it, their visitors can read it and share it, and link to it  -- and those shares and links will bring visitors into the article page on their website.

We have a large glossary on our site.  In my opinion, 1000 entries is too many for one page.  We break ours into alphabetical pages and still have a lot of entries on some of the pages.

These A, B, C pages each pull in some long-tail search traffic every day and they generate ad impressions from visitors who look at several glossary pages.

We also have links to reference pages, photos, graphics... 1000 entries is way too many.

A friend of ours has a large glossary with a generous amount of content for most of the entires.  He placed each definition on a separate page and between 1995 and 2011 made buckets of money from search traffic into those pages.  Then he got hit with a Panda problem, move to alphabetical pages and his site has recovered - still a huge income loss from those definition pages.

I agree about not using css to hide the date.  I would not hide anything on a webpage.

I don't know enough about WordPress to tell you how to do that.  It probably can be done, but I don't know for sure.

I think that a lot of articles can be written without a date if they are content that is close to being totally evergreen.   If you add a date to these articles and that date is a few years old, it can tarnish the opinion of the visitor when there is nothing wrong with the article, and the article might even be among the very best on the web.  So, I don't date a lot of my articles for that reason.

I am always upgrading articles, which is different from updating.  An update is when you add fresh news or information that is totally new about the subject.  An upgrade is when you add another section of evergreen content, add new photos, improve photos, add a video,  do a rewrite for clarity, or other type of improvement.  I notice that when I upgrade an article it often moves higher in the SERPs.  Usually just a few positions if it is on the first page, but if it is deep in the SERPs, it might move up substantially.  I've never had anything move from bottom of first page to #1, unless it moved into the featured snippet.

If you have a website with a few thousand articles and your author team is two or three people, if each of them update or upgrade one article every working day, there will be articles on your site that go a long time without an update.  Figure 200 working days in a year and a three person team.... if you have a 6000 article website that means it will take ten years to upgrade or update every article - if you do them in a straight rotation.

Keeping all of your business on one domain will help with your branding, since there is a natural overlap in buyers and sellers of auto parts.  It will expose your buyparts business to everyone to comes to the sellparts domain.

My preferred method would be to keep all of the pages in folders on the sellparts domain.  That is best for SEO purposes since Google does not give subdomains the full benefit of their root domain.  I would work hard or pay for development to make that happen.

My very last resort would be to use a subdomain.  The pages on the subdomain would not perform as well as if they were on the root domain.

If these sites belonged to me, I would not place site-wide links on either of them that point to the other.  In this situation, links from BuyParts will probably be of little to no value in lifting the rankings of SellParts since it is so much stronger.

If I thought that many customers of these sites would be natural customers of the other, then I would combine the sites.  I would test this by making a large pdf of parts that I am willing to buy, placing it on the SellParts domain and linking to it from several obvious places saying "we also buy parts, click here for our buy list".

That is what I would do if these sites belonged to me.

"buyparts.com doesn't work"

I don't want to give a response without having a clear understanding of this.

Thank you for the example, Sandi.

I just did the site: query and the pages are indexed, just not ranking well.  Perhaps the need more time.

Thanks again.

I am suspecting that Google often hesitates to index pages that have registered trademarks on them that are marked with a .   For example EGOL used in the title tag or in the

tag at the top of the page.

Registered trademarks are everywhere and most retail product pages contain at least one of them.  However, most people use the registered trademark names as text in their writing without adding the registered trademark sign of .

Have you experienced a problem getting such pages indexed or have you read any articles about how Google treats registered trademarks?