I'm offering some statistical downloads (pdf & zip) for widgets. There isn't any content to show in the web page per se nor I'm interested to insert any which isn't going to be useful to the end visitor.
I know that Google likes to rank those page having some 300-400 or more words. Less than 1% sites may be like my this site so Google would definitely like to discount my site.
I've also disallowed *.pdf and *.zip in the robots.txt so that to get those files visitors do reach my site rather than directly clicking in the Google SERP.
Though those files can be downloaded by directly clicking but I'm thinking to add a "Download" form submit button to get the download.
My thinking is that in this way Google will think that these pages have some value which is achieved by submitting a POST form button.
Is my thinking correct? What else could I do to improve page value of download pages (without adding the descriptive text to each page)?
It can work so long as the obscure phrase is not part of, or close to, a shorter, more competitive phrase. Even then, you might be lucky, but usually you won't be these days.
Google used to be very good at picking out obscure phrases that were similar to more popular ones, back when they paid more attention to the title tag and h1. But that all went out the window years ago.