I'm generally not one to quote Valleywag but their post entitled "Why sponsoring bloggers is a waste of money" is definitely worth a read. 

Even Scoble couldn't save Seagate. Almost a year after the hard-drive maker renewed a sponsorship deal with the prolific blogger, its stock is down 35 percent. Archrival Western Digital, meanwhile, is up 40 percent. So much for the profession of "influencer marketing," a field which has exploded since the 2000 publication of Malcolm Gladwell's The Tipping Point and the subsequent work The Influentials. These books, translated into action by marketers, have prompted companies from AT&T to Yahoo to hire executives expressly to suck up to bloggers. Seagate's Scoble sponsorship is the purest expression of this trend. And the best illustration of why it doesn't work.

The theory it's based on is nonsense. It is true that ideas spread virally through the population. But it turns out that there's not a single set of influencers who are reliable Typhoid Marys. Duncan Watts, a former Columbia University researcher who now works for Yahoo, found in a study that the emergence of contagious ideas is random. Repeated experiments found that anyone can start a trend, and it's impossible to predict who those people will be.

Now, like any Valleywag piece they feel the need to turn it into an attack on someone but if you look below that the idea they're putting forward is actually an interesting one. 

For those who don't know I worked at a small computer store after getting out of high school.  In said store the technicians acted both as computer repair people and as salesmen.  I don't mind telling you I was uncomfortable in the latter role at first but after making a little money off commissions I "got good" real quick. 

During this time I learned an important lesson about influence which is that it isn't worth that much.  From a salesman's perspective getting someone to buy something is about getting them excited when they're in the store.  So excited that they need to have what you're selling that very instant. 

Regardless of what the so-called "influencers" in their life told them to do.

Here's a typical scenario:

• Customer needs a new computer.
• Customers goes back and forth on it for weeks asking anyone who they think knows anything about computers what to do. 
• All those people give basically the same advice "buy a big brand"
• Customer goes on line, looks at the big brands, but isn't really excited by seeing pictures of computers so they put it off. 
• One day, Customer sees the little computer shop where Tom works and decides to drop in. 
• Tom shows customer the cool games, photo editing software, music applications, etc... that could be theirs and gets them so excited they can barely contain themselves. 
• Customer walks out with generic PC from the little Computer Shop that Tom works at. 
• Final Caveat: When asked by someone taking a survey, Customer says he "took friends advice" because people get embarrassed about making impulse buys.

It really is as simple as that.  That's why I sold so many computers and that, by the way, is why Apple's cool looking stores do so well today.  Customers don't care about the opinion of so-called "influentials" they care about being excited.  Even if that isn't what they say to someone taking a survey.

So the bottom line is that Valleywag is right on both counts.  Convincing Influencers (and Sponsoring Bloggers by extension) isn't worth much because you need to get people excited about your product and being told about it won't do that.  You're far better off focusing on advertising that shows off your product and a sales experience that pushes those exciting features. 

Because the adrenaline from that will give your customer the push they need to actually buy your product.