Some Search Engine Optimization (SEO) tactics can give you a marginal boost in rankings, but hurt you on a net basis.
The main culprit is usually an overweening preoccupation with on-page keyword optimization, but link-building can hurt too.
This article is not about black-hat SEO practices, which are covered in plenty of detail elsewhere. Instead, we’ll look at “good” SEO practices when they’re overdone.
Let’s see what gets hurt.