I've got a handful of domains that are around 15 years old and they are good brand keyword domains (no hyphens, one or two words) related to products sold on an E-commerce site. WAY back in the day, we used them as doorway sites where there was product information that each product page linked to the product on the actual E-commerce site. We shut the sites down a few years ago for fear of getting a Google penalty. However I would think these domains due to being so old and being keyword domains still have value from an SEO standpoint even today. The question is, what is the most effective white-hat strategy for using them? I could see creating professionally designed "Enthusiast Community" sites for the brands they are associated with. Throw on some brand history, blog posts about new products and toss in a discussion forum. But the big question then becomes what is the best way to funnel traffic from the community site to the main e-commerce site without Google frowning? Image ads? Since Google has no idea if the owner of the community site is associated with the site being advertised (although I would expect it would be wise to host them with different hosting services and make sure WHOIS info is private.) Obviously a more organic approach is to participate in the discussion forums, but that's sort of a given. I'm wondering more direct traffic referral approaches that are effective but have no penalty risk.