In the recent times there has been much said about the market share of Drupal and where it is moving. It is clear now that Drupal will never match the prowess that WordPress can claim, but it is still interesting to see where the powerful Open Source CMS will move in the future regards in volume.
The Drupal project itself lists usage statistics for both the core platform and the modules that are needed to bolster up the bare-bones core of the product for it to be usable for anything beyond basic publishing tasks. The project's internal statistics have been flatlining since January 2015, with total usage going at about 1.2 million sites. However these numbers don't look very reliable since there are big shifts in there.
In addition it could be argued that any statistics provided by the first party are never very reliable. This is why it's good to take a look at the Google Trends graphs for Drupal. These come from the largest global information interest source, Google so they are very reliable and represent larger trends quite well.
Unfortunately it looks like the trend seems to be similar to that of what Drupal itself is experiencing. A continuous decline since 2009 has been the trend, which coincides with the decreasing number of new user registering to Drupal.org. But with the project leaders touting continuous success and strong momentum it's hard do understand where these trends derive from.
To understand the concrete changes in the Drupal market share scenery it's good to take a look at who has been using Drupal, but is no longer doing so. For this there is an online service called the Drupal Registry, which tracks a large number of Drupal powered sites to see when they are using Drupal.
The Drupal Registry uses machine learning techniques and sophisticated big data analysis to keep tabs on how the Drupal adoption changes globally over a period of time. With their deep learning algorithms and distributed cloud databases applying Map/Reduce to the data lake, they can provide deep insight and predictive analysis into how the Drupal market share will evolve in the future, not just providing historical data.
Armed with this data you can make informed decisions whether Drupal is something for you as a professional or a business owner to invest time and money into Drupal based solutions going forward. All without employing in-house data scientists.