Perpendicular Search: The Difference between Horizontal and Vertical Search

Do you remember how Google was way back in 2004? I still do. The internet was still relatively new to my 14-year-old self back then that I still somewhat vaguely remember how Google search engine results page (SERP) look like back then. It was a couple of years after my family switched to a proper broadband connection after years of intimate struggles with dial-up and thanks to my sterling grades at the time, I was finally given a computer of my own.

Horizontal and vertical search

Right now, when I type in the word ‘Mission Impossible’ into Google, the SERP will be populated by a smorgasbord of different types of content. The right hand side is filled with what is known as Google’s knowledge card, displaying details about the first film in the series such as posters and screenshots, synopsis, cast members and other relevant search queries. The actual SERP lists Wikipedia and IMDB entries on the film and the series as a whole, news updates on the new Mission Impossible: Fallout film and trailer for that same film, plus suggestions at the bottom for other Mission Impossible films, films featuring Tom Cruise and other action films.

Had I typed in the exact same word on Google 14 years ago, all I’d get would just be articles. Wikipedia entries and IMDB entries and maybe the Rottentomatoes page of the first film would pop up in the results. If I want to look up some images on the film, I’d have to switch to Google image search and if I want to see a trailer for the film, I’d have to pop over into YouTube. Google and search engines in general have come a long way in the past 14 years.

This current version of Google search engine that we have right now uses what is called a universal or horizontal search. It pulls in contents from across all four corners of the internet, blending web pages, images, videos, news etc to provide you with the most wide-ranging result possible. The Google search from 2004 uses what is now called a vertical search, in that it only covers web pages while image and video search is covered by Google image search and YouTube. Understanding this difference and how to utilize it is crucial in understanding how SEO services work.

The universal reach of horizontal search

It is referred to as such because horizontal search is wide-ranging but shallow and would cover any topics relating to your search query. All of the major search engines, Google, Bing and Yahoo, fall under this umbrella. Generally, when someone is starting the search process for a particular object/subject, a horizontal search engine is what they start with. A horizontal search won’t always give you the answer to what you’re looking for but they can always be relied upon to point you in the right direction.

The laser-like focus of vertical search

In contrast, a vertical search is a narrow but deep look into a subject by limiting coverage into a single type of content, website or even a geographical region. There are a huge number of examples for a vertical search engine. YouTube and Vimeo for videos, Google image search for images, Google scholar for scientific journals and the search function in Amazon are several examples. If a website has a built-in search function then that particular site could qualify as a vertical search engine. Due to the specialized nature of vertical search, this is usually employed when a user already knows what they’re searching for.

So, which to optimize for?

In short, both. Using Google as an example, the SERP would display local search results depending on the query, which means that if you optimize for Google you can kill two birds with one stone, optimizing for both horizontal and vertical search. The tricky thing is in dealing with specialized websites as depending on the field of business, there can be a lot to choose from. For food alone for example, you’ve got Yelp, Zomato, TripAdvisor and even Facebook in addition to Google reviews. You have your work cut out to maintain your presence across all of those platforms.

E-commerce is where things might get a little complicated. Due to the sheer number of items available in those sites, retail giants like Amazon with their own search algorithm and SEO methods. When you start peddling your goods across different retail sites, optimizing for each would be difficult so focusing on a select few or even just one is advisable. If you operate your own website on top of that, you’re going to have to decide which takes priority in your SEO efforts.