Since the Shiki Ryuu is known for its hard stance on neutrality, after some discussion they were let in. Of course, Sunagakure didn't want to have them know that the Kazekage was kidnapped so that someone might buy that information, but since there was a branch in the village, they suspected that they already knew it anyway.
They also weren't worried about them being impersonators, because in the past when some folks tried that, they were instantly crushed by the Shiki Ryuu and blacklisted from being able to buy information from them. After that, no one wanted to risk being blackmailed.
While wandering through the village to search for the branch, Ukon said: "You know, back then I thought you were crazy for trying to build an information brokerage...and that we managed to achieve all that in only 3 years is really crazy if you think about it..."
"I really don't want to hear you call someone else crazy...but to be honest, I didn't also didn't expect this to become this big. I guess we were just lucky. Just think about it...all the shinobi villages gathered information on their own and treasured it with utmost care. But it's just impossible to gather all information they need on their own, so they and their respective nation shared information to help each other. However, small shinobi villages weren't able to do that, which put them further at a disadvantage. That's why they employed the services of small brokers who would gather information on the 5 great shinobi countries. But such small brokers obviously aren't able to get relevant information, which left a vacuum of demand. Now, if someone were to fill this vacuum, what are the things they would need?"
"Just come to the point! You know I'm an impatient guy!"
"Oh come one, don't be like that...anyway there are two things." - Eiji stopped and raised two fingers: "Relevant information and power - both things we had. We had some relevant information because of our peculiar backgrounds: Me being the former Hokage and you a former elite bodyguard for Orochimaru. After selling high desired information to a bunch of people, we started to build up a reputation. And that reputation, in turn, got us more clients, which again raised our reputation which started to snowball. However, because of that renown, people started to target us - not only shinobi villages, but other brokers as well. This is where power comes into play. Except for Chisato, without sounding too cocky, we are all really strong - there aren't a lot of people who can beat us. After being targeted for some time, we also got a reputation for being strong. Now the small brokers were out of options, they couldn't compete with our intel and couldn't crush us directly - they were essentially out of business. They either had to look for another way to earn money or be part of us. This again started a snowball effect -"
Ukon who was only half-listening stated: "But that only gave us a monopoly over the small villages while the big fish continued to ignore us, right?"
"Sigh, you are asking like you weren't with us the whole time..."
"Not my fault. You always just sent me somewhere to defeat some trash...not that I mind though."
Eiji shrugged his shoulders and just continued: "Well, you aren't wrong. The information network of the 5 great shinobi villages is high-class, so competing with them was really hard. Fortunately right at that time, Orochimaru attacked us because of Sasuke, which gave us a good reason to publish information, which even shocked the big villages. With that, even though they were reluctant at first, occasionally some would turn to us. And since we always did a good job the number of times increased. But this was also the time when our small business suddenly couldn't keep up with the demand and I started to employ ordinary civilians instead of former intel-brokers. Thinking back, coming up with a plan on how to avoid spies and managing all that, was the most tedious stuff...but now at least it operates almost automatically. Though if I disappeared, all the snakes which are crucial would vanish as well and everything would collapse...eh, who cares, I'm already rich and didn't do it for money in the first place." - Eiji opened the door to the Sunagakure branch and entered it with Ukon.