Billers, Ad Networks, Dating sites will be affected:
Online US-EU Safe Harbor is suspended. The legal framework, known as Safe Harbour, that allows 4,500 USA companies, from social media to airlines, to transfer data from the European Union to the United States, is invalid. Without Safe Harbour, such transfers are forbidden, or only allowed via other means, under EU laws that prohibit data-sharing with countries deemed to have lower privacy standards, incluiding United States (as Snowden suggested). Individual European countries can now set their own regulation for US companies' handling of citizens' data, and each EU country can choose to suspend the transfer of data to the US, forcing companies to host user data exclusively within the country. Each Eu country's national supervisory authorities, when dealing with a claim, must be able to examine, with complete independence, whether the transfer of a person’s data to a third country complies with the requirements laid down by the directive. Russia did this recently, introducing a new data law that demanded data on Russian citizens be stored within Russia.
Silicon Valley now 'illegal' in Europe: Why Schrems vs Facebook is such a biggie • The Register
EU Court Says Data-Transfer Pact With U.S. Violates Privacy - WSJ
The list of companies using the now killed US-EU Safe Harbor is there:
https://safeharbor.export.gov/list.aspx
I see there 2checkout, adbrite, adroll, coinbase, clickbooth, epoch.com LLC, friendfinder network, openx, .. really only the bigger ones, lots missing anyway, did not cared to apply for safe harbor. It looks like only USA companies are affected.. however let a company be based in Europe and host in USA (which is common) it would be silly if that's ok, as an export to USA servers is made anyway, and NSA can spy in own territory...
In list we got also "MasterCard International Incorporated", that is quite wide to all ecommerce, but I am more concerned at Epoch.com LLC for example.