And it's not getting excessive. I just clicked through 20 pages of stories, and there is less than 1 bitcoin story per page on average. Only 2 pages have 2 bitcoin stories, and none have 3 or more.
Going back pages does not give you an accurate representation of the daily front page. Also, when I go a few pages back there is suddenly a huge swathe of non-URL posts for seemingly no reason.
I lifted a dataset[1] from http://hackerslide.com which has hourly archived front pages. With that and some dumb regular expressions[2] I categorized stories and how much time that story stayed on the front page. That is, two bitcoin posts on four different front-pages in a day would be 8 'story-hours'.
I'm sure this way of measuring has problems such as different times having different amount of activity on HN.
To me it seems like there are constantly 1+ bitcoin posts on the front-page everyday. Most of the time the posts are about some trivial event (bitcoin hits 8.5 on mtgox, EFF starts accepting bitcoins, EFF stops accepting bitcoins) or a blog post that discusses bitcoin. In all of these circumstances the discussion seems to follow the same trends and go over the same ground. If there is ever a truly novel insight it would be hard to find in the mess.
