Just looking at the number of different lines of dice we stock in the store. Chessex is the dominant brand and our best selling line, mainly, I think, because of the plastic box packaging and the new color sets that are released several times a year. Surprisingly, at least here, the more expensive speckled and marbled colors outsell the flat colored opaque ones. I think our customers like to go through the sets and find one they haven't seen before to add to their collections. The flat colored opaques are common enough that everyone can find a set if they wish, but a Glow Blue/Yellow, now that's a color you won't easily find in other dice bags around the table.
Koplow is a dice line that has existed much longer than the Chessex line, as Koplow dates back to 1974, while Chessex was founded in 1987. Due to Chessex' much wider availability through distribution in the 1980s and 1990s, more stores adopted the Chessex line over Koplow. Koplow dice, for our store, have never achieved more than marginal sales with their Train Dice Game the best selling item that we stock from the company.
A second line that does OK for us, not nearly as well as the Chessex colors, is the Valiant Games line. For years, Valiant allows us to custom design sets for the store and even tag them with the store logo. Their pricing structure allows us to offer a 9 dice bagged set with our logo on the hang tag for the same MSRP as a similar Chessex set. However, customers still seem to prefer the Chessex line, likely becasue of the familiarity of the packaging and the ever changing selection of colors.
A third line that did much better when it first released was the Crystal Caste. The company came out with a line of oblong dice that really piqued customer interest. A bit pricier than the more standard Chessex and Koplow dice, the Chrystal Caste dice sold extremely well when first released, but that fascination waned and over the last few years, thought it still sells the oblong crystal dice, Christal Caste has recast itself, so to speak, as a more mainstream dice company, offering dice styles similar to those from Valiant, Chessex and Koplow, as well as a few innovations, such as the d1000 and semi-precious stone dice.