I'm looking at analyzing the market for selling consumer product information,
from the point of view of a data aggregator looking to sell sets of
product data to web retailers.  I.e. assume I have a database of
product information (size, weight, model #, photographs, price etc),
and a team of people working on growing this
database, and would like to re-sell this data.   I need to understand
this market better, and specifically need to know:

(a) How large is the market ($ terms) and growth rate?  How does one
go about calculating this, given that most retailers do this in-house
today?
(b) Who are the major players in this market (one major player is cnet
channel - they have a 1.5 million SKU database - are there any
others)?
(c) Any major trends (e.g. standardization) you see affecting this market?
(d) In seeling to this market, how would you segment the customer base?