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Hello, While I can't confirm this, my understanding was that you can't have a penalty on http and not on https (and vice versa). The domain or sub-domain is where the penalty would be (to my understanding - could be wrong?). Although Google sees http://www.domain.com/blog/ and https://www.domain.com/blog/ as two different URLs, I believe a penalty for thin content would be cast on domain.com, thus affecting both URLs. I'd suggest moving all pages to https and ensure your blog content is not thin.  If you're struggling for time to create great blog content, cut down on your volume and post better quality less often. That'd be the safest strategy IMO. Goodluck!