Most if not all of the articles I read on Influencer Marketing are Business to Consumer (B2C) related rather than Business to Business (B2B). So while in the world of B2B we are not selling lipsticks and driven by the Kardashians it is driven by the same rules and regulations.
In the UK it's driven by the Advertising Standards Authority (ASA) and in the US Federal Trade Commission (FTC). In fact as Social Media is global, you have to comply with FTC regulations.
The FTC recommends hashtags like #ad and #Impartneringwith[brand], while it deems the likes of “#sp,” “Thanks [brand]” or “#partner” ambiguous.
If you are looking for more information on Influencer marketing, (with case studies of where it goes wrong and right) I wrote this introduction on out blog.
Influencer Marketing: An Introduction http://www.social-experts.net/influencer-marketing-introduction/ via @DigitalLeadersA
A further 49% said they weren't aware of the hashtags and language – terms like #ad #spon #sp – which are used to disclose commercial relationships between brands and influencers.