\afterpage not called after page break

Question

In this example

\documentclass{article}

\usepackage[a6paper,landscape,margin=1cm,bottom=2cm]{geometry}
\usepackage[english]{babel}
\usepackage{blindtext}

\usepackage{afterpage,refcount,lastpage}
\newcommand{\testafterpage}{%
    \noindent{\Large\ttfamily NEW PAGE!\quad}%
    \afterpage{\testafterpage}%
}
\AtBeginDocument{\testafterpage}

\begin{document}
\blindtext[3]
\end{document}

the words NEW PAGE! should be printed at the beginning of every page using the afterpage package. For some reason, NEW PAGE! is not inserted at the second page of the document:

Is this intended behaviour? Is it possible to fix this in general?

I am aware of the various packages like atbegshi that allow to add some content when the page is shipped out, but I don't know if this can also be used as a replacement for the strange behaviour of afterpage.

Answer 1

\newcommand{\testafterpage}{%
    \noindent{\Large\ttfamily NEW PAGE!\quad}%
    \afterpage{\testafterpage}%
}

Is definitely not guaranteed to add text on to every page. The recursive call will add \afterpage at the point the page breaker was exercised to ship out the previous page but if more than one page worth of text had been collected then this is the wrong place.

\afterpage is an incredibly invasive, fragile mechanism: it's not designed at all to be used consistently through a document in this way.

% This package implements a command, |\afterpage|, that causes the
% commands specified in its argument to be expanded after the current
% page is output.\footnote{This is really a pre-release, to see whether
% people like the idea of a command like this. This implementation is
% \emph{not} particularly robust. This implementation does not work in
% two column mode, and can get `confused' by \LaTeX's floating
% environments.}