1.587362 multiplie each year (double every 18 months - moores law) 1.4 multiple each year 1.4 multiple each year
Flash (capacity in Gb at given price) HD 1-1.1" (capacity in Gb at given price) HD 1.8" (capacity in Gb at given price)
  $9 $60 $200 $60 $100 $200 $60 $100 $200
                   
1998 0.00 0.04 0.09            
1999 0.01 0.06 0.15            
2000 0.01 0.09 0.24            
2001 0.02 0.15 0.38           5
2002 0.02 0.24 0.60         5 10
2003 0.04 0.38 0.94            
2004 0.06 0.60 1.50   2 4   20 40
2005 0.10 0.95 2.38   3 6   40 60
2006 0.16 1.51 3.78   4 8   56 84
2007 0.25 2.40 6.00   5 11 ?? 78 118
2008 0.40 3.81 9.52   8 15   110 165
2009 0.63 6.05 15.12   11 22   154 230
2010 1.00 9.60 24.00   15 30   215 323
2011 1.59 15.24 38.09   21 42   301 452
2012 2.52 24.19 60.46 ?? 30 59   422 632
2013 4.00 38.39 95.98   41 83   590  
2014 6.35 60.94 152.35   58 116   826  
2015 10.08 96.74 241.84   81 162      
Bold = actual data point (from memory)
Items in colour = point at which the tech (fundamentals) suggests a disruption -- but other factors are relevant
1 CD - attractive if very cheap, insertable into player and complimentary software makes it easy to load up with an album
5 CDs - most people's happy carry around set, attractive if it's as easy to select and change the 5CDs as looking at your CD shelf and taking 5 CDs with you
30 CDs - most people's working set - attractive if it's easy to select what to play from the large number of tracks
30Gb - most peoples wildest audio collect OR reasonable store for working set of videos
We suspect there is also a sizeable niche around 100-200Gb for owners of large collections
If somehow portable video players take off -- are you kidding? -- then there will be a key size around 100-400Gb too
The key disruption point is in red -- the UI/software isn't available, and is unlikely to become available, for the 1&5 CD points to be able to carry the mass market
This suggest a key opporuntity for say a phone company to get a window of high sales by creating the right UI/software by 2007/2008 (when $9 of flash gives enough capacity to carry a chunk of the mass mobile music market IF there is software to integrate well with a larger PC and/or online collection).
Most of this will be disrupted at some point by online storage (ubiqitous networking) - though the $9 of storage will persist in the device.