Meaning:

“流量” means “web traffic,” “花” means “flower,” which in fact refers to “young actress,” and “生” is short for “小生” which means “young actor.” Web traffic is the amount of data sent and received by visitors of a particular website, which is determined by the number of visitors and the number of pages they visit. Large web traffic indicates the popularity of a website, and similarly, when we call an actor or actress “流量花生,” he or she has a huge fanbase and frequently creates a buzz online. As opposed to actors and actresses who make their names with their performance prowess, this group become popular because of their good looks and the buzz about them.

Example:

A: 演技不行唱歌跳舞不行，上综艺节目也很木讷， “流量花生”为什么那么多人喜欢？

Yǎnjì bùxíng chànggē tiàowǔ bùxíng, shàng zōngyì jiémù yě hěn mùnè, líuliàng huāshēng wèishénme nàme duō rén xǐhuan?

These “heavy-traffic” young actors and actresses can’t act, sing or dance well, and are slow to react on variety shows. Why do so many people love them?

B: 靠颜值，也靠炒作。

Kào yánzhí, yě kào chǎozuò。

Because of their good looks, and also thanks to media hype.