Seen some of the sponsored content for Shadow of Mordor popping up on Youtube, some of it masquerading as first impressions. Look for disclosure buried in the description, but don't assume anyone who doesnt have it is secretely on the take. It's reasonably unlikely that any sensible channel would forgo disclosure and risk their business over one brand deal (since disclosure is required under FTC regulations). That stuff should be "unavoidable" according to the FTC though (source: http://ubm.io/1rIhX57 and clearly some channels havent learned that yet.