... people who buy on overstock or tigerdirect are just buying more bitcoin to replace what they spent. They originally bought the bitcoin as an investment, they are excited to be able to use it for something, but they don't want to exit their position. ... The takeaway is that the selling pressure is lower when you take into account the behavior of current retail bitcoin customers.
I agree with jmw. Merchant adoption probably does create some downward pressure on the bitcoin price (short term only) for the reasons that were well-articulated in Vinny's article [1] (which is one reason why I brought it to the attention of this thread), but jmw points out why that downward pressure may be limited.
I don't think this was mentioned in the article, but here's another source of short-term downward pressure on the bitcoin price: I wonder how many early adopters are currently selling off bitcoin to cover unexpected capital gains taxes? I for one played around with arbitrage in 2013, not realizing that when I bought from exchange A at $200 and sold at exchange B at $210, I was incurring capital gains. (Luckily my base was 2011, so it's long term cap gains. And luckily I am fundamentally a hodl'er, not a day trader, so my cap gains was pretty small.)
[1] Finding Equilibrium : Searching for the true value of a Bitcoin
Vinny Lingham, CEO of Gyft
https://medium.com/p/ba5f3fcce103