Affect on SEO of multiple domain names pointing to same site

After reading multiple forums and blog posts, there doesn’t seem to be a definitive answer on whether or how pointing multiple domain names to a single site affects a web site’s search engine results. Domain names with key words relevant to our business were registered and pointed to our main domain via a 301 redirect.

Does anyone here have any experience with it?

Thanks in advance.

I did find this in a Google document SEO Starter Guide that makes me feel a little more confident:

[quote=“Google SEO Starter Guide”]Provide one version of a URL to reach a document

To prevent users from linking to one version of a URL and others linking to a different version (this
could split the reputation of that content between the URLs), focus on using and referring to one URL
in the structure and internal linking of your pages. If you do find that people are accessing the same
content through multiple URLs, setting up a 301 redirect from non-preferred URLs to the dominant
URL is a good solution for this
.[/quote] (Bold/italics mine)

[quote=“CraigTPE”]I did find this in a Google document SEO Starter Guide that makes me feel a little more confident:

[quote=“Google SEO Starter Guide”]Provide one version of a URL to reach a document

To prevent users from linking to one version of a URL and others linking to a different version (this
could split the reputation of that content between the URLs), focus on using and referring to one URL
in the structure and internal linking of your pages. If you do find that people are accessing the same
content through multiple URLs, setting up a 301 redirect from non-preferred URLs to the dominant
URL is a good solution for this
.[/quote] (Bold/italics mine)[/quote]

Yeah! that’s old school though and actually doesn’t make a big difference.
The number of links to an URL doesn’t count this much any-more. It’s rather more important to get a single quality link.
Links with a high number of click-throughs seem to have a high value.

Read the google webmaster guidelines and play by those rules.
Have an HTML content driven site without spamming keywords.

Have your keywords within complete sentences and forget about this google page rank. It doesn’t have much value nowadays.

There used to be the problem when you had different versions of the same page. for example www. homepage .com or homepage.com or com/index.html vs. com/index.php where the google algorithm would trigger a duplicate content filter and devalue all those pages. This isn’t a problem any more, at least, that’s what I have observed.

Trying to figure that stuff out will make you insane. Nobody knows for certain, but they all like to pretend they do. As Hamleintaiwan already mentioned, just focus on good links. If you aren’t spamming links, then I wouldn’t worry.