How RLSA works
RLSA attaches a remarketing audience, a list of people who previously visited your site, to a Search campaign or ad group. When someone on that list searches a relevant query, you can treat them differently: bid higher because they already know you, or open up broader keywords you would not bid on for cold traffic because the warm audience makes them worth it. There are two modes: observation, which only adjusts bids while still showing to everyone, and targeting, which restricts the ads to appear only for people on the list.
Why RLSA lifts efficiency
A past visitor who searches again is a fundamentally better prospect than a stranger typing the same query. RLSA lets you pay what that difference is worth instead of bidding the same for both. On competitive head terms that are too expensive for cold traffic, an RLSA layer can make them profitable for warm audiences. On generic queries where cold traffic converts poorly, higher bids for returning visitors capture the users most likely to buy. The lift comes from matching bid to genuine intent difference rather than treating all searchers as equal.
RLSA vs customer match
RLSA and customer match both bring first-party audiences into Search, but from different sources. RLSA is built from site behaviour, the people who visited pages, viewed products, or abandoned a cart. Customer match is built from data you upload, such as your email list of existing customers. They are complementary: RLSA reaches recent site visitors, customer match reaches your known customer base, and layering both lets you bid differently for a cold searcher, a recent visitor, and an existing customer all searching the same term.
How iClick uses RLSA
iClick layers RLSA onto Search campaigns in observation mode first, using the bid difference between warm and cold searchers to reclaim head terms and generic queries that are unprofitable for strangers. The rule is to price the audience difference from evidence, bidding warm visitors up by what their better conversion rate actually justifies, and to reserve targeting mode for campaigns deliberately built only for returning visitors. RLSA and customer match are layered together so each searcher is bid to their real intent.
