GRACE KAO What a week. I just returned from days 3 and 4 of BTS’s concerts in Las Vegas. BTS performed in Allegiant Stadium to sold-out crowds of approximately 65,000 for four nights (May 23, 24, 27 and 28). The concerts were amazing and, notably, BTS danced more than they did when I saw them in Goyang, Gyeonggi Province. Unlike the Korean shows, it was an indoor concert, so there were no fireworks. While one can watch concert fancams on YouTube, I’ll share what the experience was like in person.These shows were a bit different because Las Vegas attracts more out-of-town visitors. In fact, I did not meet a single person from Vegas. What I found instead were Army sojourners from all around the world with their freebies in hand. I think those who travel for BTS concerts also plan for intricate freebies.Most BTS concerts do not take place in a city full of casinos, so there were more indoor spaces for Army to occupy. In fact, I became accustomed to greeting strangers with the phrase, “Hello Army," as people wore clothing from the tour and swag that indicated members of the group or their corresponding BT21 characters. There were also many hand-decorated and custom-designed shirts and bags. I was prepared to hand out freebies at the concert, but actually, the exchange began as soon as I entered my hotel lobby the morning after my late-night arrival.Two hotels were attached to the pedestrian bridge that led people directly to the stadium. I don’t know if these hotels had more concert attendees than other hotels, but they certainly had plenty of Army. Also, one of these hotels had the “Welcome to Borahaegas” sign that was a popular photo backdrop. “Borahae” is a term that fans have translated to “I purple you” — a phrase that member V has used to address Army.My first concert in Vegas was on Wednesday, day 3 of the set. I met my sisters, who traveled from California, as well as my friend, who is also from Connecticut. As we walked from one of the hotel lobbies to the stadium, we saw dozens of Army mulling around. When we reached the second hotel, we saw about 75 people exchanging freebies. For those of you who are new to K-pop and BTS, it is customary to bring packets of goodies to give or exchange with other fans. These items range from candy, stickers, photo cards, thematic bookmarks made to look like concert tickets, poker chips and playing cards (appropriate since we were in Vegas), keychains and bracelets.While not a scientific sample, everyone I spoke to was from other states, including California, Washington, Arizona, Colorado, Texas, Oklahoma, Kentucky, Florida, North and South Carolina, Tennessee, Pennsylvania, Texas, etc. I met people from Canada (Vancouver, Edmonton and Winnipeg). There were many Japanese visitors. Interestingly, among the people I spoke with, the single most common country of origin was Mexico. One person told me, “I had no choice since I couldn’t get a ticket for Mexico.”While the crowd was almost exclusively adult women, I did see a few men and families with elementary school-aged children participating in the gift exchange. After 45 minutes near the escalator, we were asked to leave by the casino staff.At this point, we headed to the stadium. It was a short walk to the bridge and then across to the stadium. While we waited in line, there were more gift exchanges. In fact, I received so many gifts that I could no longer fit them in my plastic see-through bag as stipulated by the venue. Outside, the most impressive gift I received was a hand-crocheted tangerine with Shooky’s face on it — this was in honor of the fact that Suga (whose BT21 character is Shooky) once said that he liked tangerines. This gift-giver told us that each tangerine took an hour to make and that she learned to crochet for the sole purpose of making this freebie. From the size of her bag, she likely made 75 to 100 of these.Someone handed out macarons shaped like different BT21 characters, and we ate them before the concert. I also received a hand-sewn heart commemorating the date, a first-aid pack with alcohol wipes, bandages and some acetaminophen. Someone even gave us a tube of sunscreen and another person handed out hand lotion.The second day was much of the same, but by then I had received so many freebies that it was hard to keep up. My modest freebies were packs of stickers and photo cards I printed, and I was happy to give them out. One of my sisters handed out tassels and another bracelets. All of the gifts were given and received with great appreciation.On the second day of our concerts, a woman behind us held a bottle of lemon water and offered to spray anyone with it to alleviate the heat.Inside the venues, there were more gift exchanges. In fact, I handed out sticker packs at the airport and even on my flight home. The women next to me and behind me were all Army, and we were all still on the post-concert high. Was it because we were in Vegas that the freebies were so plentiful? I don’t know. However, I think I need to up my game for my future concert freebies.- - -Grace KaoGrace Kao is an IBM professor of sociology and professor of ethnicity, race and migration at Yale University. The views expressed here are the writer’s own. — Ed.