Dividend exchange traded funds have sucked in over $10 billion so far this year but now some winners and losers are starting emerge in this red-hot and developing ETF sector.

For example, the two most popular dividend ETFs in 2012 are WisdomTree Emerging Markets Equity Income (NYSEArca: DEM) and Vanguard Dividend Appreciation (NYSEArca: VIG).

The oldest ETF in the category is iShares Dow Jones Select Dividend Index Fund (NYSEArca: DVY), but the Vanguard fund VIG has surpassed it in total assets.

Also, DVY places only fifth on the list of best-selling dividend ETFs this year. [The 10 Top-Selling Dividend ETFs of 2012]

“Dividend-focused exchange traded funds that offer a decent yield and instant diversification have been wildly popular in recent years, thanks to the paltry yields in fixed income. To satisfy investor demand, ETF providers have launched a slew of new products,” says Morningstar analyst Michael Rawson.