describes links with the intent to increase PageRank i.e. improve Google Search Rankings.

There are two cases:

  1. Manipulative links can be a risk for your rankings. Manipulative links become toxic links - and hurt your rankings, if they are discovered by Google.
  2. Manipulative links can be a reward for your rankings. If manipulative links are not discovered by Google, then those are the links that drive the SEO economy and link building ever since.

Links are created either as

  1. unsolicited links or natural links, or
  2. solicited links or unnatural links - according to Google, which are essentially manipulative links - if they do not have a NoFollow tag

The reason they were created doesn’t (yet) decide if links are dangerous (“toxic”) or not for your rankings.

Only when Google decides that a link is “unnatural”, and Google must be very sure for that, then this manipulative link gets a higher risk for causing a penalty.

The degree to which we think it will cause problems for your rankings is measured in Link Detox Risk® in LRT.

Just because a link is deemed riskier than others, doesn’t mean it’s a toxic link, or even causes a penalty.

TL:DR Manipulative Links are links without NoFollow link tag, created by webmasters or consultants hired by the webmasters. They can be toxic or not.

In a more recent article Mary Haynes came up with a classification of links where Manipulative Links were a separate category to Toxic Links.

This does not make sense, since Manipulative Links only become risky if discovered/detected by Google - and that is not the case for many manipulative links. Why? The industry of link building would cease to exist if Google could spot and penalize every manipulative link.