I am searching for detailed information related to the online printing
industry.  I am referring to companies that either primarily transact
business over the lab for the purpose of selling printed goods or for
companies that have a mix between a physical presence and a web site
that also have a significant amount of web-based business. 
vistaprint.com is an example of an online printing company that I am
referring to.

I am looking for the following information:

I'm looking for a list of the top printing companies in terms of their
gross online sales, their off-line sales are not important.  This
number may either be an exact number if possible or an educated guess
based on factual information.  I would like this list to include a
minimum of five companies and preferably about 10.  More is certainly
acceptable.

Out of the companies that offer printing online.  I would like to know
which companies.  You can determine are simply a reseller or affiliate
for another company out of the major companies.  You find online, in
terms of the major companies, you find online.  I am referring to four
example.  When you type, digital printing or postcards or business
cards into a global search and take a look at the first three to five
pages of ad words results.  You will see the companies that I referred
to as the more major players online.  If you find print companies that
don't happen to be advertising on google is find to include those as
well.

All of the companies, you list, I would like to have a list of the 10
most successful online print web sites, their Web addresses, and a
copy of their pricing information, if at all possible.

Any additional information that may help me ascertain what aspects of
their web sites are most effective in terms of producing sales and
producing profits will be of great benefit.

If it is possible, I would also like to know what the average printer
is spending for keyword placement in systems like Google ad words for
common print industry keywords such as digital printing business
cards, letterhead stationery, etc.

It would also be a benefit if, the gross dollar volume of sales for
these companies could be found, especially if the gross dollar volume
applies only to their online sales if it applies to both their online
and off-line sales.  Please make sure to note that.

Please ask if you have any additional questions that I have not
covered here.  If you come across relevant or related information on
this subject, feel free to include it if it is useful.  I will
cheerfully provide an appropriate tip.