Multiple SEO blogs with identical content. Will Google punish me?

I would recommend you slightly tweak each site's content, may be get a rewrite service to rewrite those content with same meaning but in different words, that work best for Google and human!

Try and make each at least 30-35% unique

Google will definitely punish it, if you are using the exact articles in all the blog sources. It is also better advised to change a bit of the articles before publishing it on other sources. Exact articles would be considered as duplicate and can be punished by google also.

yeah, you need to buy a content spinner like "the best spinner" or something similar and make sure that each piece of copied content is at last 30-35% unique, better to try to get that figure to around 50% though.

What's the purpose of having 3 different domains?

It may work just fine for you to do a 301 redirect to a primary domain. This is what a lot of organizations do when the buy the .com along with several other extensions, the .com has the content and the other domains simply redirect to it.

If you're targeting toward different markets with different domains, then do things to make your content fit the target. If your content is mismatched with traffic it would hurt your conversion rate.

From a SEO perspective, having the duplicated sites will create a challenge for ranking since the first one Google comes across will be considered the original and the others typically won't rank well absent heavy duty link building or site authority. It's not what I'd call 'punishment' but just accurate ranking. There are ways to have significant partial duplicate content, such as product descriptions, while not having this ranking dampening effect but which to use will depend on factors that haven't been mentioned here.

Doesnt make any sense to do that anyway, just write unique content for all your diff blogs and target different keywords with each blog post, will take ages but will be worth the effort !

Doing it the way your thinking is askin for trouble

Woc

Thank you for the excellent advice everyone,

The reason we have bought three domains is that these are three different keyword phrases that mean the same thing. Our thinking was that if we could dominate all these three keyword phrases (all of them being valid for our product), then we could channel loads of traffic to our website.

We are new to this, so we may be wrong, but we're quite confident that this approach will work.

So what I take from this is that we should definitely write unique content for each blog. The problem of course is that since all the phrases essentially mean the same thing, it is hard to find unique content for each one. Would it be better to drop two of them and simply focus on the best one (which looks incredibly promising)?

I have been wary of using content spinning as I've felt it is a low-integrity practice, but maybe that's just an odd idea I have. I'll look more into it.

Thanks again. You are very helpful.

Eivind

PS! The above means - no, there will not be redirects

How about changing the design for each site? it wont be good to have same content for them since google checks for duplicate content every now and then. Alter some parts parts or simply spin. You can use easyarticlespinner.net or thebestspinner.