Reddit’s “Churning” section is a popular hangout for people looking to take advantage of the various credit card signup bonuses while avoiding the pitfalls of damaged credit and debt. And recently, the churners got another bonus—an unofficial AMA (ask me anything) session with someone who used to approve or deny card applications for Citibank.

For those who only have a few credit cards—or none—”churning” is when you regularly apply for credit cards that have big bonuses, spend all your money on them to be eligible to collect them, and then stop using the card and move to the next one. If a credit card has a fee, churners will typically ask the credit card company to demote the card to a non-fee version.

In dozens of responses to the eager Redditors looking for every bit of information to optimize their credit situation just a little bit more, the former Citi (C) employee clarified some longstanding questions and provided insight into how the process all works. Since banks and credit card issuers aren’t typically eager to share their process, this was a big deal for the online community.

The credit evaluators don’t care about churning, they care about creditworthiness

According to the Redditor (many AMAs aren’t anonymous but this one was, likely due to a nondisclosure agreement) who said they left the company in 2013 and is now an accountant, credit card companies typically wouldn’t notice or care if you have 20 credit cards open—the hallmark of a churner. The only anti-churning policy they have is an automatic rejection by the computer if another Citi card was approved within the past 90 days. Instead, approvers only focus on a few things, because they have just 90 seconds to decide. In most cases, the approver doesn’t even know if there’s a bonus for the card you’re applying for. They’re just looking at the applicant’s creditworthiness.

A person’s financial situation is often complex, but it all boils down to a good credit score. What factors go into a good score? No “derogatory marks” in your history (like a bankruptcy), the number of inquiries (fewer the better), and a low utilization ratio. A lot of mystery surrounds the utilization ratio, the amount you spend as a portion of your credit limit, and the former Citi employee clarified that it’s total utilization across all cards that’s key. There’s no downside in maxing a $1,000 card that gives you good rewards if you have another credit card with an unused $2,000 limit. “The goal is under 30% with all your cards, and we used that standard,” he wrote, echoing the conventional wisdom.

The AMA unearthed a few other credit card and banking secrets. For Citi, at least in 2013, a “long-time customer” was someone with a 20-year-old account. Those customers would warrant more consideration than 90 seconds per credit card application.

Another interesting tidbit: most of the time, self-reported income is rarely verified, but it might be if the cardholder’s profession didn’t line up with the ballpark salary.

Being nice is nice, but it’s not important

Another one that many Redditors wanted to know was whether being nice helps when you’re on the phone asking for a new credit card, lower rate, or higher limit. While it undoubtedly makes the situation more pleasant for all involved, it didn’t really do much because the phone agent doesn’t have much discretion when it comes to approving customers’ requests. They have to stick to the script. In fact, the only reason computer algorithms didn’t simply do everything is that the system was “antiquated.”

While none of these insights is particularly groundbreaking, the demystifying was certainly appreciated by many of these bonus-hunters. “Not sure if you knew this,” one Redditor wrote, “but your responses are precious to us churners.”

Ethan Wolff-Mann is a writer at Yahoo Finance focusing on consumer issues, tech, and personal finance. Follow him on Twitter @ewolffmann. Got a tip? Send it to [email protected].

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