[mechanical_fish]

If true (and I'll assume it is) this is just a basic conversion-funnel problem. If your funnel looks like this:

  - user takes photo on their iPhone
  - user successfully learns of Flickr's existence
  - user successfully opens Flickr account
  - user successfully uploads photo to Flickr
  - user successfully navigates to Flickr, sees photo
  - user decides to order prints
  - user finds and navigates "order prints" workflow
  - user gets prints in the mail three days later

...your conversion rate is one number. If your funnel looks like this:

  - user takes photo on their iPhone
  - user decides they like photo and want a print
  - user goes to local store which has sold photo prints for 30 years
  - user hands camera and $5 to store employee
  - user receives prints ten minutes later

your conversion rate is a completely different number, and it would not be surprising to learn that number B is orders of magnitude different from number A.