Catching Bots With A CAPTCHA

Posted by Robert Cerff in Management on 02 July 2013

Tags: online marketing, spam, website maintenance, website update

A CAPTCHA is a program that can generate and grade tests that humans can pass but current computer programs cannot. While these are most commonly seen as letters often mixed with numbers in a bizarre and often barely legible font types, others could be simple math problems or images.

The main reason for including a CAPTCHA at any point on a website is to restrict access, primarily that of a computer program or otherwise malicious script.

CAPTCHAs have several applications for website security which may include:

1. Preventing Comment Spam:
These are those comments that rarely make any sense or try to seed a comment with links to pharmaceutical website, online gambling websites or other undesirable website.

2. Protecting Website Forms:
To keep your mailing or alert base as clean as possible, it is sometimes necessary to ensure that those subscribing are indeed a legitimate lead.

3. Preventing Scraping or Indexing:
This is a little more technical, but prevents other automated scripts from copying all of your content and displaying it elsewhere or being returned in a search results page.

There are however often drawbacks from implementing a CAPTCHA on a website.

1. Reduction in conversion rate (direct enquiries and subscriptions)
The introduction of a CAPTCHA adds in an extra step in the conversion funnel, general rule is that the more steps required the lower the conversion rate. 2

2. Lower accessibility
CAPTCHAs may not be accessible on certain devices or by those who are unsure or unable to make use of a CAPTCHA.

3. Renders the website less effective.
A reduction in the number of visitors that may be able to interactive with your website or by making the interaction process longer there is generally a lower return from your website.

We at Prop Data suggest that you don’t have the CAPTCHA control set to on as the default option. This ensures that visitors have easiest access to the website and there are minimal barriers to making an enquiry or subscribing to a service.

Should you notice a drastic increase in spam the CAPTCHA functionality can be switched on quickly for all forms in the management system with a simple click of the mouse. We do however recommend that this only be active for 24-48 hours. Usually spam comes in waves, once the script spamming your website can no longer access your forms itusually stops.

If you’re still undecided on how to best use CAPTCHAs on your website, contact Prop Data for further advice.