As far as I understand, you do not need to create a separate profile
for 'https://' vs. 'http://'. It is perfectly fine to create just a
single profile. And you can just use the SSL version of the Analytics
script on every page. The only reason to setup multiple profiles in
your case is if you wanted to track things differently somehow for one
protocol vs. the other (unlikely) and found that creating separate
profiles was somehow an easier way to execute your tracking plans vs.
using filters, etc. within the same profile (also unlikely).
Technically speaking, it is slightly "better" to use the 'http://' code
in NON-SSL pages because the file "urchin.js" will then be cached by
the end-user's computer and only downloaded once for all 'http://'
pages whereas the file "https://ssl.google-analytics.com/urchin.js"
will never be cached by the browser (no files loaded over SSL should
ever be cached by the browser). So the 'https://' version will be
downloaded in full every single time.
In "real life" though (as Fred previously mentioned), doing things this
"better" way probably will make no measurable difference to the end
user since the "urchin.js" is not a very large file. It might make a
difference to Google's bandwidth costs though (but I imagine they can
probably swing the cost!). :)
I want to point out one additional "obvious" tidbit to other people who
might stumple upon this thread. The SSL URL for the Google Analytics
code is under a different sub-domain than the non-SSL URL.
NON-SSL: http://www.google-analytics.com/urchin.js
SSL: https://ssl.google-analytics.com/urchin.js
This third URL may appear to work at first, but it is WRONG!
WRONG!!!! --> https://www.google-analytics.com/urchin.js
You should never use that last URL to load the SSL version of the
'urchin.js' file. It actually does laod the file, but the problem is
that the domain name "www.google-analytics.com" does not have its own
dedicated SSL certificate. The certificate for that domain is
registered to the domain "www.google.com" NOT to
"www.google-analytics.com". Most end-users using Internet Explorer will
never know the difference, but some browsers (such as Firefox) actually
popup a "scary" and confusing (to average users) error message saying
something like, "...the certificate is not registered to the domain
"www.google-analyutics.com". Someone may be trying to interecept your
data..." The end user can click "OK" and everything will be fine, but
it is more likely IMO that the average user will probably get out of
your website as fast as they can after receiving a message like that.
SO, THE MORAL OF THIS STORY IS, NEVER USE:
BAD BAD BAD ---> https://www.google-analytics.com/urchin.js
FOR SSL PAGES ALWAYS USE:
GOOD GOOD GOOD --> https://ssl.google-analytics.com/urchin.js
Cheers!