I have a blog post in my head about this, and how links-as-currency is is a really broken system. Travel sites are a great example.
Companies like TripAdvisor literally have an army of 30-40 people whose sold job is link building and they measure how many they are able to generate per day. They literally calculate the "cost-per-link".
So, while they are not buying text links (which Google forbids), they ARE hurling manpower at linkbuilding in a systematic way.
So, if a link is a "vote" and Google is democratic, many SEO-centric sites like TripAdvisor are hiring people to drag voters to the ballot box and persuade them to vote for them.
I did an analysis on this a while back that told the same story, there is a blog post that includes a nice visualization of the share of travel search categories across the companies mentioned in the article:
Companies like TripAdvisor literally have an army of 30-40 people whose sold job is link building and they measure how many they are able to generate per day. They literally calculate the "cost-per-link".
So, while they are not buying text links (which Google forbids), they ARE hurling manpower at linkbuilding in a systematic way.
So, if a link is a "vote" and Google is democratic, many SEO-centric sites like TripAdvisor are hiring people to drag voters to the ballot box and persuade them to vote for them.