Why don't Amazon reviews have permalinks? If they did, they could become first-class bits of web content with a currency in the world of ideas. Amazon would benefit because it would bring readers in.
Also, what if Amazon items had trackback so that you could review them from your own CMS?
Further: why don't browsers have some subtle way to surface the anchor tags (fragments) on a page? The purple pilcrow thing could be automatic.
The bookmarklet available here will expose the anchors for you.
Mike: I think the trouble with putting the numbers ahead of the paragraph is that it's hard to format that way. CJCS and PMC have been doing it that way since their inception, so it's part of their typesetting style.
Regardless, this author thinks that purple pilcrows are grand, as they are an instance of what the blog world needs more of: tools that enable conversations (as opposed to pontifications, that is).