Hi, Ty (the author and investor)here, I should have been more clear. This was how I was rating this deal and other recent deals. It is clearly a bigger factor when you really like something but don't have the nerve to make the plunge. And for some new investors it might be 80% of why they invest--just jump on the bandwagon, and you can brag you're in a deal with XYZ. The bandwagon effect is most pronounced when people hear that a deal is about to close. But then it's not so much WHO is doing the deal, but rather that something scarce is going to slip away, and you just have to COMMIT NOW or lose that hot deal. An entire advertising industry is built around this human need.
I love AngelList, (www.angel.co), it's a great source of well-vetted deal flow, but the inflow is huge, and every deal has already been sponsored or invested by someone or other. So you have to learn to tune that stuff out. I may be kidding myself on the 5%, though. If I knew that Jason Calacanis was going to be taking a piece of some new deal that would go through the roof as soon as they generated some inbound traffic...I would really want to know more. But that goes more towards Team and Sales strategy, as opposed to Investors.