In general all Plone books are trending upwards, which is not unexpected considering that the Plone 3 titles are being replaced by Plone 4 ones. Martin Aspeli's Professional Plone 4 Development tops the chart so to speak with a sales rank of 156K with de Alba close behind. Plone Live once again is in the basement (at the top of the chart), but that is more likely due to its heavy reliance on non-Amazon sales channels.
The table of the current titles and their sales ranks are given in the table below. Of interest this time is the column on sales/yr. I found a graph that illustrated the approximate Amazon sales rank function, which turns out to be a power law. A little regression with Open Office Calc gave me an equation of
f(x) = (1.3*10^6) * (x^-1.1)This equation has numerous potentially huge sources of error, but I thought it would be interesting to toss it out and let the authors themselves reflect on the results. Please note that these are Amazon-only numbers. Because most titles are published by Packt, this almost certainly is a small fraction of total sales.
|Amazon Page Rank Stats||November 2011|
|Professional Plone 4 Development||Aspeli||156,335||150||4.50|
|Plone 3 Intranets||de Alba||192,392||120||4.00|
|Plone 3 Theming||Williams||704,159||29||5.00|
|Professional Plone Development: Plone 3||Aspeli||692,760||30||4.67|
|A User's Guide to Plone 4||Nagle et al.||755,217||27||n/a|
|The Definitive Guide to Plone (2nd ed)||Delmonte, et al.||984,891||20||1.00|
|Building Websites with Plone||Cooper||1,050,568||19||3.71|
|Plone 3 Products Development Cookbook||Giménez & Romero||1,270,629||15||4.00|
|Practical Plone 3||Knox et al.||1,025,403||19||4.80|
|The Definitive Guide to Plone (1st ed)||McKay||1,239,686||16||4.14|
|Plone 3 for Education||Rose||1,722,143||11||4.00|
|A User's Guide to Plone: Updated for Plone 3||Lotze & Nagle||1,773,374||11||3.00|
|Plone Content Management Essentials||Meloni||1,801,775||10||3.11|
|Content Management with Plone: Handbook||Lotze& Theune||1,954,272||10||n/a|
|Plone 3 Multimedia||Gross||2,833,640||6||3.67|
I'd like to find out what actual sales numbers are directly from authors, but only if you don't consider it SBI, "sensitive business information".