Over the past few years, the exchange-traded-fund industry developed a reputation for creating a seemingly over-the-top number of products. But it turns out that the industry was just warming up.

To the surprise of even fans of ETFs, financial firms in 2011 turned up the already fast rate of production to unprecedented levels. From January through the fall, the $1 trillion ETF industry had unveiled 287 new funds -- a rate of nearly one new one each day. That's up 29 percent from all of 2010 and double the number that debuted in 2009. Among the new additions are products geared to track the price of soybeans, German government bonds and even firms involved in the fishing business. All told, there are more than 1,400 exchange-traded products for investors to choose from. But what's most surprising is that industry insiders don't expect all of these products, or even many of them, to be successful. "They are throwing spaghetti against the wall to see if it will stick," says Mariana Bush, who follows ETFs for Wells Fargo Advisors. "It usually doesn't."

Some noodles are stickier than others. The Market Vectors Agribusiness ETF (MOO), which tracks an index of stocks involved in farming (and has the amusing ticker symbol MOO), is up 22 percent since it launched in 2007 and has attracted more than $5.8 billion in assets. For every successful ETF launch, though, there are several duds. PowerShares, which has more than 130 products, launched the Global Wind Energy ETF in 2008; that fund has lost two-thirds of its value and now has just $18 million invested in it. (PowerShares declined to comment.)

The industry defends ramping up ETF production. "Investors want as many colors in the palette as possible," says Noel Archard, managing director at iShares, the largest ETF brand by assets. But the companies do seem aware of the danger of oversaturating the market. Barclays, which has created two dozen new exchange-traded securities so far this year -- more than any other company -- says it carefully reviews investment concepts before putting them on the market. Individual investors should keep a look out for ETFs that don't attract a large amount of money quickly, planners say. Not only are ETF companies manufacturing an increasing amount of new products, but they've also stepped up another process: killing off underperformers. After a brief hiatus, firms are closing ETFs that haven't attracted a big following (they return any money to investors, but a closure can create bookkeeping and tax headaches).