<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>ComputerGuru</author><text>I always loved how despite the massive domain differences, the ISBN situation is &lt;i&gt;extremely&lt;/i&gt; similar to the IPv4&amp;#x2F;IPv6 situation (except more aggressively rent-seeking), with prefixes leased out to the old dogs, concerns about eventual address&amp;#x2F;isbn exhaustion, a scheme for mapping old ISB10 to new ISBN13 codes, etc etc.</text><parent_chain><item><author>bloak</author><text>Google has claimed that about 130 million books have been published (that factoid is all over the web). The number of 10-digit ISBNs is 1000 million (there&amp;#x27;s a check digit) and people have only just started using 13-digit ISBNs that start with 979 instead of 978; but of course there must be lots of wasted ISBNs, for example when a publisher optimistically buys a big block and then goes bankrupt. Both those numbers suggest that the &amp;quot;ISBNdb&amp;quot; with less than 31 million ISBNs is far from complete.&lt;p&gt;The frequency of each top-level prefix (which tells you the geographical or language region) would be interesting. That would the first thing I&amp;#x27;d calculate if I had the data on my disc.</text></item></parent_chain></comment><story><title>ISBNdb dump – how many books are preserved forever?</title><url>http://annas-blog.org/blog-isbndb-dump-how-many-books-are-preserved-forever.html</url></story>
<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>23skidoo</author><text>I&amp;#x27;m a little perplexed by the ISBN system. The whole centralized affair, where you have to purchase ISBNs seems like a racket. ISBNs cost more in some countries (America) than they do in others (Canada). Not for any reason other than that they can get away with it.&lt;p&gt;Much better would be a UUID generated from unique values, like a hash of the timestamp and publisher of a book. If you limit the length and number of the fields you hash to generate the UUID, you could even prove there will be zero collisions and eliminate any need to collision checks and thus an organization that charges money.</text><parent_chain><item><author>bloak</author><text>Google has claimed that about 130 million books have been published (that factoid is all over the web). The number of 10-digit ISBNs is 1000 million (there&amp;#x27;s a check digit) and people have only just started using 13-digit ISBNs that start with 979 instead of 978; but of course there must be lots of wasted ISBNs, for example when a publisher optimistically buys a big block and then goes bankrupt. Both those numbers suggest that the &amp;quot;ISBNdb&amp;quot; with less than 31 million ISBNs is far from complete.&lt;p&gt;The frequency of each top-level prefix (which tells you the geographical or language region) would be interesting. That would the first thing I&amp;#x27;d calculate if I had the data on my disc.</text></item></parent_chain></comment><story><title>ISBNdb dump – how many books are preserved forever?</title><url>http://annas-blog.org/blog-isbndb-dump-how-many-books-are-preserved-forever.html</url></story>