By and large, when you say nice things about a stock within the Dow Jones index, you don't expect a lot of angry emails. It looks as if Citigroup (NYSE:C) is the exception to that rule. After suggesting a quarter ago that Citigroup looked like an interesting long-term pick, my inbox got really full, really fast, with a variety of "how could you"-type emails.

Well, folks, fire up your email again because I'm back with the same message.

Simply put, Citigroup's second-quarter results were skunky. Revenue fell by 3% (stripping out charges), and earnings from continuing operations dropped by 7%. Both of those results missed Wall Street's mean estimates.

The interest rate market was especially unfriendly to Citigroup. A flat yield curve slammed domestic net interest margins by 52 basis points -- one of the worst drops I've seen so far among banks -- and revenue from the fixed-income business sank by 28%. What's more, a combination of higher bankruptcy filings and the decision not to pursue some riskier types of loans has hurt the consumer business.

Elsewhere, the wealth-management business was flat, and the corporate/investment banking business suffered a 15% drop in revenue. The transaction-services business did quite well, with revenue rising by 21%, and the bank's equity trading business was up 40%, but the troubles in fixed income and a slight decrease in investment banking dragged down the overall company performance.

Even so, I still think Citigroup is worth a thought for investors looking for long-term holdings. Citigroup's international consumer business is growing pretty nicely, and the long-term potential of exploiting international banking markets has almost become cliche.

What's more, even with pokey performance, Citigroup still managed an 18% return on equity and $2 billion of share buybacks during the quarter. Top that off with an above-average dividend yield and a slightly below-average P/E, and you have an interesting money-center bank investment prospect.

I have no doubt that I'm going to hear again from those who hate Citigroup, and that's fine with me. After all, value often seems to follow when most investors don't want anything more to do with a company or its stock.

We've grouped together more takes on Citigroup below:

Fool contributor Stephen Simpson has no financial interest in any stocks mentioned (that means he's neither long nor short the shares).