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What Is Web Scraping? (How it Works and Why it’s So Valuable)

April 30, 2019

From research studies to product listings, the web is not only filled with great content but valuable data as well.

But with more than 2 billion websites and resources live on the web today, sifting through and finding the “best” information manually is simply not feasible. As a matter of fact, I’ll say it’s impossible.

However, thanks to some crafty development over recent years, there is a way to automate the volume and variety of data collected from the web. This is made possible with something called “web scraping.”

What is web scraping?

In the simplest terms, web scraping – sometimes referred to as web harvesting – is the process of extracting data from websites. But why is something like this valuable in the first place?

With this in mind, you may already see some of the obvious value in web scraping, but we’ll touch on that a bit later. First, let’s understand from a basic level how the process of web scraping works.

How does web scraping work?

To grasp web scraping, it’s important to first understand that web pages are built with text-based mark-up languages – the most common being HTML.

A mark-up language defines the structure of a website’s content. Since there are universal components and tags of mark-up languages, this makes it much easier for web scrapers to pull the information it needs.

Parsing through HTML is only one-half of web scraping. After that, the scraper then extracts the necessary data and stores it. Below is a visualization of what the work of a web scraper may look like:

what-is-web-scraping

Web scrapers are similar to application programming interfaces, or APIs, which allow two applications to interact with one another to access data.

There are a few ways to scrape the web today.

  • One can hire a developer with experience in data extraction to write a bot (or web crawler) to find the information they need. These developers are fairly easy to locate on freelance platforms with the right search.
  • A project of large scale, or for those with limited coding experience, could benefit greatly from the use of web scraping tools. These tools are more niche, but you can find them in our “other analytics software” category.

5 uses of web scraping

Entire business models have been centered around the practice of web scraping, and we’ll only continue to see more examples of this in the future. Below are 5 of the more prominent applications of web scraping today.

1. Contact extraction

You may or may not be aware of it, but somewhere on the web, there’s a good chance your phone number or email address could be extracted. In web scraping, this is called contact extraction.

A tool like Hunter.io crawls the public web and scrapes what it believes to be the correct email address along with any available phone numbers. While the information isn’t always 100 percent accurate, it still makes cold outreach more efficient.

2. Price comparison

If you’re a “low-price hawk” like I am, I’m sure you’ve interacted with a price comparison tool at some point in the past.

By price scraping product or service websites, there are tools that are able to offer real-time price comparisons and fluctuations. A real-world example of this today is a tool like Hopper, which provides customers with the cheapest flight options to selected destinations.

3. Coupon and promo code extraction

Similar to price comparison tools, the web can also be scraped to extract coupons and promo codes. We see this already with web platforms like RetailMeNot and mobile apps like Honey.

While the success of these tools varies (and companies get more clever with their promo offerings), it’s still worth seeing if you can save money before checking out.

4. SEO auditing

One of the more lucrative ways web scraping is applied today is for SEO auditing.

Basically, search engines like Google and Bing have hundreds of guidelines when it comes to ranking search results for keywords – some carry more value than others.

SEO software scrapes the web, amongst other things, to analyze and compare content on search engines in terms of SEO strength. Marketers then use this insight and apply it to their day-to-day content strategies.

To understand the value of SEO software in greater depth, check out more than 200 tools listed in the category.

See the Easiest-to-Use SEO Tools →

5. Social media examination

More advanced uses of web scraping are actually able to monitor data feeds. The most prominent example of this being social listening tools.

The purpose of social listening is to scrape and extract real-time data feeds from social media platforms like Twitter and Facebook. This information can be used to examine quantitative metrics like comments, mentions, retweets, etc., and also qualitative metrics like brand sentiment and topic affinity.

Tip: We look at the differences between qualitative and quantitative data, and why one is harder to analyze than the other.

What are some web scraping limitations?

Web scraping is not a perfect, by-the-books process. This is because the “semantic web” is not yet here.

Key term: When we say the semantic web, we mean standardized web page structures and data formats across all sites. It’s sometimes referred to as the “golden age” of information access and exchange.

So, what exactly are some of the limitations of web scraping?

  • There are many subtleties and nuances when it comes to building a website. Even with website builders and templates, you’d be hard-pressed to find two websites with the exact same layout and style-guide. This is an obstacle web scrapers have to overcome.
  • Keep in mind, websites written with messy code can also influence the effectiveness of a web scraper. Things like on-page advertisements can add to the noise.
  • In addition to technical barriers, some websites have data and content usage guidelines which may prohibit web scraping; this is most often the case with sites that use proprietary algorithms. To protect their content, these sites may use encoding to make web scraping near-impossible.

It’s also worth noting that in some areas of the world, web scraping is strictly against the terms of use of websites. Because web scraping is still relatively new, there are some legal grey areas on the types and quantities of data that can be extracted.

Web scraping on the rise

It's evident that web scraping is something that will continue to be on the rise in the coming years, and touch new industries with new use-cases. As a matter of fact, a 2019 report from The Hill found that 36 percent of investment management professionals now use web scraping to derive valuable data.

What other applications of web scraping do you see? It may just be the next “big thing.”

For more insight on how industries plan on acquiring and applying big data, check out our roundup of 44 noteworthy big data statistics.

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