Therefore, those businesses are likely to increase supply in the market (by moving coins out of hoards to the market), rather than demand. Basically, they induce holders to sell, and make it convenient to do so. Are they also inducing non-bitcoiners to buy bitcoin? It is not obvious: if you had dollars and no bitcoins, why would you choose to pay with bitcoin?
I did not expect the "using bitcoin kills bitcoin" argument from you, I thought you were a little better than that.
And I did not expect to have that observation (which is not mine, many bitcoiners have been saying so) replaced by a completely different statement in order to dismiss it.
I will give you an example. Suppose @JorgeStolfi is in the US and decides to buy a fancy 3000$ laptop. He can send 3000$ to the merchant; or he can send 3000$ to Bitstamp to buy 5 BTC, then send the BTC to BitPay and have them send the 3000$ to the merchant. Which one will he choose?
Now suppose it is @Aminorex who decides to buy that laptop. He can send 3000$ to the merchant, or he can get 5 BTC from his holding, that he mined for pennies in 2010, and send them to Bitpay, who would send 3000$ to the merchant. Which one would he choose?
(And Bitpay then would sell @Aminorex's 5 BTC on the market, where they would be bought by @SroomsKit with his 3000$ which cost him many baked potato dinners. So, simplifying the equations, @ShroomsKit would pay for @Aminorex's laptop; but maybe one day he will get his money back, and more, from some other optimistic investor...)
and Aminorex could also immediately buy back his coin at market, the net impact to himself is the same. He is down $3000 in savings but now holding more fiat than in BTC. If he wishes to maintain his BTC holding he will simultaneously buy the bitcoin, - in fact coinbase have enabled this functionality. Bitcoin is an enabling function on the internet, a method of transferring value from one place to another without the necessity for expensive middlemen - banks or even Bitpay/Coinbase. Bitpay is only necessary until bitcoin is adopted as more than a commodity after all.