Please see below a quick breakdown on “Irrelevant Back Links”
Web browsers, like Google and Yahoo, have similar kinds of algorithms they use to rank websites. Each and every page, image, backlink or internal link is crawled, indexed and ranked according to the relevance of the content, as well as SEO practises adhered to. . Below is a list of potentially harmful backlinks, or Irrelevant Backlinks as suggested by Jessica;
Private blog Networks
This is not so common, but worth a mention. Some bloggers have a list of irrelevant websites they own, and they would be more than happy to list your website on each of these at a fee (Normally). Having backlinks to sites like these is detrimental to your search engine ranking.
If you have secured multiple backlink opportunities with several websites, it is essential to ensure that the copy for each of these websites is not explicitly the same. Search Engines negatively rates duplicate content.
Poor quality copy
Backlink content should be relevant to the keyword as well as the content, Search Engines disregard content that does not have relevance, and this will affect your rating.
Only using ‘DoFollow’ links
When it comes to using external links. The general rule is to only ‘DoFollow’ links that are from authoritative websites (ie. Google, Youtube and Amazon). Lesser authoritative or - ranked sites should always be ‘NoFollow’ links.
Search Engines are able to detect large-scale link exchanges between websites and does not view those as relevant backlinks. Ensure your backlinks are from sources relevant to the content on your website and that they are strategically placed within the copy.
Advertorials are a good marketing practice but can be a bad link-building practise. Search Engines negatively view advertorial content with a ‘DoFollow’ link, ensure all advertorial content has been set ‘NoFollow’.
Keywords selected for content should be used wisely. Your Search Engine ranking will be determined positively if you use variations of your selected keyword. Avoid keyword-stuffing, that is overusing the keyword in an attempt to positively influence your search engine ranking.
We do not know anything about Jessica or the SEO company that she is posing to represent. I would suggest ignoring the mail that she has sent however, it is important to ensure the best SEO practises are followed when creating content for any website. Search Engines regularly crawl websites and index them according to their relevance and SEO best practises.
I hope this offers the client a basic idea of what most Search Engines acknowledge as bad or less favourable backlinking practises.