When Moz first created the Spam Score metric, it began using an aggregate of 17 ‘spam flags’ to indicate whether a site was spammy. Over the years, using machine learning and big data sets of penalized/banned domains, they have relied on 27 different factors, which they now refer to as Spam Score Signals.
Low MozTrust to MozRank Score
MozTrust and MozRank scores are two of the most important metrics used by Moz to determine the trustworthiness of a website. If a website has a lower MozTrust score than its MozRank score, there is a high chance of it being spammy. They use a scoring scale between 1 and 10, with a higher score indicating a better chance the site is trustworthy. It is important to check these scores with Moz’s Link Explorer.
Large Site with few links
Any site that has a lot of pages, but very few links throughout indicates that the content of those pages have no real value in them. This tells search engines that these pages are not worth linking to, and thus considered spam.
Low link diversity
This flag indicates that the majority of inbound links are from a handful of domains. For example, if a site has 500 inbound links but only 5 linking domains, then it is generally considered to have low link diversity. In other words, if those 500 links came only from 5 sites, then this flag would be applicable.
Ratio of dofollow vs nofollow links
While it may not appear that important, you should pay attention to the ratio between dofollow vs nofollow links. If the number of inbound do-follow links of a site are much higher than no-follow links, it indicates the site may not be earning those links naturally.
Minimal branded anchor texts in inbound links
Today, simply making specific keywords as anchor texts is not going to do too much for your page ranking. We recommend a balanced ratio of different types of anchor texts to ensure your links are optimized well. Sites that are organically linked tend to have lots of links with branded anchor texts.
Thin content
After the release of Google’s BERT algorithm, websites need to step up their game in providing top-quality content. The search engine is making sure it helps users get the best results for their queries. Moreover, with so much content out there these days, visitors are also looking for something in-depth and reliable.
Small site markup
Site markup consists of things like JavaScript, CSS, and Schema. The actual purpose of a site markup is to enhance the experience of the user. Therefore, sites with little markup like basic HTML, poor structure, a heavy page with little formatting and low-quality graphical elements are clear signs of spam.
Low number of internal links
Websites that have a lot of valuable pages and content will be more likely to have internal links. In addition, internal links help users stay longer on a website, indicating a meaningful experience for a user. Sites that have a low number of internal links may be marked as spam.
External links in navigation
Often times, sites that are built for a user do not have external links on their navigation menus. If there are a lot of external links in those areas, it can often be mistaken that they are those places indicating pure advertising.
No contact info
Reputable sites always have contact information, no matter what type of site it is. This can be included in a header or menu, and visitors should always feel like they can correspond with the administrator.
