Mid-cap stocks have been solid performers for most of this year, helping turn investors attention to traditional cap-weighted exchange traded funds that track the well-known S&P MidCap 400 Index.

Alternatively-weighted mid-cap ETFs have impressed as well, including those that focus on dividends or profitability. “Constituents in the S&P Mid Cap 400 Index are expected to generate 20% earnings growth in 2014 and 18% growth in 2015. This is above the 8% and 11% growth expected for the S&P 500 Index,” S&P CapitalIQ recently said, indicating it could still be a good time for investors to consider a different spin on the traditional mid-cap ETF experience. [Alternative Mid-Cap ETF is a Winner]

One way of doing that is with the RevenueShares Mid Cap Fund (NYSEArca: RWK), which weights the members of the S&P MidCap 400 Index by top-line revenue.

Weighting by revenue makes sense because bigger revenues usually mean bigger profits and better businesses. Further, market cap doesn’t always reflect a firm’s underlying business value. [Revenue Weighting Works for These ETFs]

Other RevenueShares ETFs have proven the revenue weighting strategy can be beneficial for investors. For example, thanks to its massive utilities exposure, the RevenueShares Ultra Dividend Fund (NYSEArca: RDIV) is one of this year’s top-performing dividend ETFs. [A High Yield Dividend ETF With Big Upside]

RWK is up 6.15% year-to-date, or about 30 basis points better than the largest ETFs that track the S&P MidCap 400 Index.