A2 Milk and Australian vitamin maker Blackmores are often lumped in together because the unofficial "daigou" trade channels are are a big part of their businesses.
But while A2 milk's share price has being going ballistic, Blackmores' has been heading south - with daigou at the centre of it all.
The ASX-listed company this week posted a slump in third-quarter profit, partly due to a new China e-commerce law which came into force during the quarter.
The new rules mean that some goods sent to China through e-commerce channels need to adhere to higher product safety standards and a stricter tax regime.
Blackmores said the move resulted in lower sales to Chinese consumers through Australian retailers or personal shoppers in Australia who sent goods back to China.
In contrast, a2 Milk has said it has had no impact from the new Chinese e-commerce laws that came into effect in January.
The company does not report quaterly, but it said early this month that it was making "pleasing progress" for Chinese label and English label cross border e-commerce channels.
Investment bank UBS, in a comprehensive report on the China's infant formula sector, said a2 Milk looked to be gaining market share at the expense of its bigger competitors.
In its report, UBS said data pointed to a stronger first half performance from China's Beingmate. Beingmate is 18.8 per cent owned by Fonterra but the co-op has the investment under review.
The investment bank said Beingmate's share of online best sellers recovered back towards levels reported 12 months ago.
"At the same time, we have seen a sequential lift in online median price for Beingmate. However, it is too early to suggest that Beingmate online market share is sustantialby improving." Beingmate's share price has doubled over the last six months to 8 yuan.