...or next week.What’s considered gray hat SEO today might be black hat SEO next year.
Those are all considered "black hat" by Google and heavily penalized upon discovery..Some grey hat techniques are:
Using paid links
Publishing duplicate content at different sites
Unnatural keyword density
Grey hat , I don't Found This As officially announce World in Representation of SEO , Gray Hat is hypothetical Word that is Comes under Introduction For those Who Prefer Both White hat as Well Black Hat Techniques in promoting their Business .Gray hat SEO is SEO techniques that take more risks than white hat SEO techniques but aren't likely to get your site banned from search engines. Some Gray Hat SEO services tend to use more dubious devices and take bigger risks.They're questionable SEO techniques but not in the same category as black hat SEO techniques.