Any SEO benefit to multiple 1-page sites pointing back to our main site?

Question

Over the years we have registered quite a number of domains, but we only use one for our business. Currently, all those other domains just sit, parked with the registrars.

All the unused domains are made up of words or terms related to our main business in one way or another, but which aren't necessarily used enough in our main website to get us ranking very high if someone should happen to search those terms... so our thinking was that maybe by having simple sites set up for each of those domains, we'd be more likely to be found if someone did search those terms.

Is there any SEO benefit to setting up simple, 1-page sites for each of those unused domains and having a few sentences about the specific part of our business offering related to the domain name and then a link to our main site?

If there might be, would it also be best to set a canonical url even though the content of each won't be exactly the same as what's on the main site (or each other)?

Answer 1

All the unused domains are made up of words or terms related to our main business in one way or another, but which aren't necessarily used enough in our main website to get us ranking very high if someone should happen to search those terms... so our thinking was that maybe by having simple sites set up for each of those domains, we'd be more likely to be found if someone did search those terms.

This can prevent search engines from identifying a website and/or web page relevant to the search query associated with the entity (s) specified in the content of these web pages. In this case, search engines can simply ignore the content of such websites or web pages.

Is there any SEO benefit to setting up simple, 1-page sites for each of those unused domains and having a few sentences about the specific part of our business offering related to the domain name and then a link to our main site?

Not.

If there might be, would it also be best to set a canonical url even though the content of each won't be exactly the same as what's on the main site (or each other)?

Yes, you can set a canonical meta link that Google will say:

To specify which URL that you want people to see in search results.

However, in this case, it is completely incomprehensible for the purpose of creating non-canonical separate websites, because these websites will be excluded from the search results. Moreover, it can be perceived as an attempt to manipulate search results. This in turn can be the reason for manual actions.

Summary: Using duplicate content (even for an incomplete content match) for standalone websites can lower the search rank of such websites simply doesn't make sense. Also, such websites with duplicate content can be the reason for the ban from Google. Just run away from duplicate content on separate websites.