Why would you be tempted to sign up to a ‘blogger influencer network’?

Would love someone from the vendor side to explain to me why they’d be tempted to sign up to a ‘blogger influencer network’. I can understand them being misled by the title into thinking they’d be connecting with real influencers, but outside of those people, and once they’d realised that wasn’t the case, why would a vendor contact one of these database hawkers? Their databases don’t hold influencers, they hold the names of tweeters and bloggers who, in exchange for payment, are willing to write promotional guff while not declaring it to whatever readership they have. How ‘inauthentic’ can you get?

So someone tell me what’s the attraction?