Most people I know here personally get their money down here in a combination among three different means:
1) They bring back cash when they go the States.
2) They have friends who are going to, or are in, the States who bring back money for them - transfer money to the friend's bank or pay him or her pesos when they get here.
3) They know someone down here who has pesos and wants dollars. To differentiate from #2, you would be talking about people down here who earn a LOT of pesos (an owner of a hot business, for example). A business might convert those pesos into dollars (arbolitos and cuevas need pesos - that's where they get a lot of them, though usually on the scale of a number of somewhat-successful businesses trying to survive, but there are the occasional booming businesses) because there are so many and they don't want even a week's loss of value in the peso. I won't get into publicly why that benefits the company who's already bought dollars. Most can probably figure it out.
I only know one guy who goes to Uruguay to pull out his money there. Relatively costly and time-consuming.
I don't know anyone personally who would use Xoom or particularly Western Union, to get money down here except in the most dire of needs. But most of the guys I know are well-established down here, from more than a decade to no less than five years, or are really good friends with someone here already and gets the ropes shown to them quickly. It takes time to learn the ropes and make the contacts most times.
Many of us who earn our salaries from outside the country, or have money outside the country in one fashion or other, denominated in dollars or euros, spend an inordinate amount of time chasing our tails accomplishing this. It's not a huge percentage of our time overall, but compared to walking down the street and taking pesos out of the cash machine it's significant. Oh, for the days when that was possible and all people were bitching about were the fees the machines or the banks charged us. I weep at night thinking about it. Heh.
I can hear a number of you out there thinking "poor boy." I feel so much sympathy for those who earn their money is pesos. I'm the only one in my married-into extended family who does and I watch them struggle every day with the rising prices and the weakening of the peso; meanwhile the government tries to clamp down and, no matter the mid- to long-term consequences, does every stupid thing in the book to try to manipulate the market to keep them a few more days in power. I can't believe anyone in the government, at this point, thinks there's a happy ending around the corner. And here I, as well as many of us (at least who I know), live within blocks of a huge reservoir of thousands or poor people in Villa 31 who could be moved to stir like hornets in the right depressive circumstances.
That's the real meaning of the black/blue market. Greed and relative inhumanity on a large scale (per-capita) and the effects it has on a lot of people in a lot of ways. The market itself is just an indicator, as always - as well as a tool for those who can use it.
