These sites were also living and dying by organic traffic from
Google.
But once Google’s Panda update rolled out in 2011, many websites
saw much, if not all, of that traffic vanish overnight.
Google provided some insight on what counts as a high-quality
site.
Aimed at eliminating low-quality (or thin) content, Panda was
updated periodically over the coming years, eventually becoming
integrated into Google’s core algorithm in 2016.
With websites still recovering from the effects of Panda, Google
unleashed a hotly anticipated over-optimization algorithm, intended
to eliminate “aggressive spam tactics” from its results.
Eventually dubbed Penguin, this algorithm targeted link schemes
(websites with unusual linking patterns, including a high-amount of
exact match anchor text that matched keywords you
wanted to rank for) and keyword stuffing.
Penguin wasn’t updated nearly as frequently as Panda, with more
than a year passing between some updates. And, like Panda,
Penguin became part of Google’s real-time algorithm in 2016.
20 YEARS OF SEO: A BRIEF HISTORY OF SEARCH ENGINE OPTIMIZATION