It means "to attract traffic".
It's a term of online marketing / e-commerce, highlighted also by the terms "线上 = online" and "线下 = offline".
attract traffic online, convert offline ("convert" as in customer, or lead, conversion)
Your understanding, as also others pointed out, is essentially correct, but I believe the contraction is from：
吸引流量 (流量 = traffic）
which makes more sense, if you look at it from the point of view of typical Chinese chiasm abbreviations:
omitting the least semantically relevant character of each word, without having to specify 顾客, even though, yes, "traffic" to an online shop comes from customers.
Compare with English, in the same e-commerce context, where "traffic" alone is a fairly well understood and self-explanatory word.