The AMP project was launched in October last year. In February, AMP stories began to be featured in the "Top stories" section of its search results. Now they are to be expanded.

In its announcement, Google says that since February it has seen a "incredible global adoption of AMP that has gone beyond the news industry to include e-commerce, entertainment, travel, recipe sites and so on".

AMP pages are built differently to normal HTML pages and load much faster on mobiles. Pages that have AMP versions appear with a small lightning like GIF next to the search result.

Facebook has its own mobile-focused version of a Web page, supplied through its Instant Articles format. Clicking on a link loads a proprietary Instant Article from participating publishers.

Given the extent to which publishers are dependent on Facebook and Google for Web traffic, this effectively means that an online publisher would have to build three versions of a Web page: one for AMP, one for Facebook Instant Articles (if one is a participant), and one with bog standard HTML.

It also means that both Google and Facebook can promote what they wish to promote and downgrade what is not in their interest to promote. Despite protests aplenty from both behemoths, there have been plenty of cases where bias has been demonstrated.

For example, it is well-known that Eric Schmidt, the chairman of Alphabet, Google's parent company, has set up a startup to provide the engineering talent that Hillary Clinton would need to win the forthcoming US presidential election. Hence there is no prize for guessing what Schmidt, a very powerful man in the Google hierarchy, would like the average US voter to read on the Web.

It is also well-known that the word search means different things to Google and the average person: two people can search for the same term and get startlingly different results, purely due to the fact that they have different interests – what is known as the filter bubble.

Recent digital advertising statistics have shown that Google and Facebook dominate. The acceleration of the use of proprietary Web page formats is only going to increase that domination.

The AMP format is not closed, but given that pages built to that spec load faster, they will also figure higher in Google search rankings. Which increases the probability of someone clicking on them.

With every move made by the bigger Web players, it looks like independent publishers, who are actually responsible for most of the readable content, will be gradually shut out.

What these predatory outfits will do when content disappears altogether is left to be seen.