A Practical Guide to Retargeting

Marketing budgets have taken a real hit since last fall, and the tactics gaining traction right now are the ones that can prove their worth in a single report rather than asking a finance team to trust a brand argument. Retargeting, showing ads specifically to people who already visited your site, fits that moment almost perfectly, and a small group of specialist vendors has built real businesses around doing it well.

The basic mechanics

When someone visits your site, a small piece of code drops a cookie in their browser. If they leave without converting, which the vast majority of visitors do on any site, that cookie lets a retargeting vendor recognize them later as they browse other sites in an ad network, and show them a banner tied specifically to your business rather than a generic ad. Because you’re reaching someone who already showed real interest, retargeting consistently converts far better and costs far less per acquisition than prospecting for entirely new visitors.

Who’s running this well

A handful of dedicated vendors have emerged specifically to handle retargeting, rather than treating it as a minor feature of a broader display network. Criteo, a French company that’s been expanding aggressively into the US market, has built its retargeting technology around dynamic ads that automatically pull in the exact products a visitor browsed on an e-commerce site, rather than a single static creative for everyone. Fetchback is running a similar model. Both are worth evaluating against the retargeting features bundled into larger display networks, since the dedicated vendors tend to have more sophisticated matching and more inventory to place ads into.

Why this is spreading so fast right now

Three things are converging. First, the recession has every marketer looking for spend they can defend with a clear number, and retargeting produces one of the cleanest return-on-ad-spend stories in display advertising. Second, e-commerce sites in particular are sitting on huge volumes of visitors who browse and leave, representing recoverable revenue that was previously just lost. Third, the technology to do dynamic, per-visitor creative at scale has only become practical in the last couple of years, so it’s a new capability rather than an old idea getting rebranded.

The catch nobody’s budget seems to account for

Retargeting is easy to overdo, and doing it badly damages the relationship it’s meant to rebuild. Showing someone the same banner for the same product for weeks after they’ve already bought it, or bombarding a single visitor with a dozen impressions in one browsing session, reads as intrusive rather than helpful, and it burns budget on people who were never going to convert anyway. A few disciplines matter here:

• Cap frequency deliberately. There’s no reason a single visitor needs to see your ad more than a handful of times a day.
• Stop retargeting people who already converted. This sounds obvious and is commonly missed, and it’s pure wasted spend.
• Segment by intent. Someone who abandoned a full cart deserves more aggressive, timely retargeting than someone who glanced at your homepage for ten seconds.
• Refresh creative regularly. A visitor seeing the exact same static banner all week tunes it out fast.

Where the honest measurement trap lives

Because retargeting only reaches people who already showed interest, it’s prone to taking credit for sales that would likely have happened anyway. A retargeting campaign that reports a spectacular return on ad spend deserves a skeptical second look, not just celebration, and the more disciplined advertisers are starting to run small holdout tests, withholding retargeting from a portion of eligible visitors, to see what the tactic adds rather than what it simply claims.

Retargeting is one of the few bright spots in a difficult year for display, precisely because it’s built around an audience that’s already proven itself rather than one you’re hoping to convince cold. Used with real restraint on frequency and honest measurement of what it’s adding, it’s earning the attention it’s getting.