Should I 'backfill' a brand new site with PLR content to get started?

If you are strictly talking about appearance for readers, than yes you can backdate some posts for engagement purposes.

I do.

if you are setting up a wordpress blog make the setting for not contacting the bot so it does not ping out until you are ready to tell the world, but still have some content if someone stumbles upon the blog

Ed

Search engines like Google give importance to the date stamps for ranking fresh content, so it may not be a good strategy if you wish to rank that content. And make sure you rewrite those PLR articles before publishing them.

You won't trick Google into thinking it is older content and PLR won't trick visitors into thinking you are a serious quality site they want to visit again. No matter what date you assign to PLR it will not help your website.

It is a perfectly good strategy to post PLR on your blogs, backdated or not, provided it is well-written and provides a useful experience for your visitors.

Google don't (in their own words and in my experience) penalize you for using PLR in the sense of delisting your site completely. They will not - usually - rank pages that contain PLR or count them towards any measure of authority for your site. But that is a far cry from penalizing you.

What they WILL penalize is the use of the same article on multiple pages of your site. These days it seems odd to even think about posting the same article over and over again on the same blog or website, but go back ten years when people were churning out 'Made for Adsense' sites, that's exactly what they were doing.

Google soon woke up to that and started delisting those sites as fast as they could find them. Hence people started talking about a duplicate content penalty. But they never did penalize individual sites for using the same content as other sites beyond the fairly recent move to not include such pages in their index.

There can be all kinds of reasons why a site would want to use PLR without changing it up enough to satisfy Google that it is fresh content. For one thing, not all sites rely on Google (or other search engines) for their traffic!

The OP's reason of wanting to build a site with a depth of content from the get-go, so that human visitors see an established site with lots of content, is perfectly valid and is probably one of the most common uses of PLR.

The key to it all is to make sure the PLR you use is top quality and not some of the language-garbling crap we have all see far too much of. Thankfully there are quite a few PLR vendors around who care about quality and so finding the good stuff isn't all that hard.

I've used PLR a lot lately to fill some new blogs and I've found myself learning a lot from reading the articles themselves. Sometimes I find myself reading for ages. I agree that a new person reading a good tip isn't aware that that tip might be posted elsewhere online nor do they care if it helps them a little bit. If it's useful and well written there's a chance that a reader's going to appreciate it.