out of those, how many are uploaded to "free" services (like oFoto,
Yahoo, Shutterfly) and how many are uploaded to "paid-for" services
(like Picturetrail, Smugmug, Photoreflect, etc ?

I use Shutterfly myself and for sharing my photos online, that is
free!  You can also use Ofoto and I think that enables you to share
photos online also free of charge. Both of these services offer high
quality digital prints if you are interested in that as well.

thank you, banjobarry-ga.

the problem with shuterfly, ofoto, and the likes is that photo albums
end up looking like crap surrounded by all the ads and offers of
buying prints. they might do good job printing but they certainly do
not know how to present photos nicely, that just not their business.
that's why most people opt to go to a nicer pay service, like pbase or
smugmug and pay them some small fee per year (about $30-$50) for good
quality and unlimited storage.

i am still looking for an answer to my question to get an idea for the
percentage of people.

     -alex