Vet­er­ans hold­ing media jobs in mobile adver­tis­ing agen­cies over the last few years will be acute­ly aware that, when it comes to ad retar­get­ing, they’re con­front­ed with a yawn­ing mobile adver­tis­ing gap. Ad retar­get­ing serves users dif­fer­ent, rel­e­vant ads depend­ing on which sites they’ve been brows­ing — and it’s much, much hard­er on mobile devices.

Any­one with any kind of media jobs expe­ri­ence in online adver­tis­ing can tell you that click­throughs on retar­get­ed ads are sub­stan­tial­ly high­er than on ran­dom dis­play ads. But retar­get­ing on mobile devices presents some big hur­dles. Apple’s iPad and iPhone brows­er blocks third par­ty cook­ies. How do you retar­get when you can’t drop a cookie?

Tapad to the rescue

That’s where clever star­tups like Tapad come in. Found­ed two years ago in New York by Are Traas­dahl – the man behind ring­tone com­pa­ny Thumb­play – Tapad can ana­lyze hun­dreds of data points, includ­ing con­tent source, brows­er type and device type, and then tar­get ads to con­sumers across device plat­forms. And it claims it can do so with 70 – 75 per cent accuracy.

That may be one rea­son why it’s just attract­ed $6.5 mil­lion in Series B fund­ing from some heavy­weight investors. The round was led by First­hand Tech­nol­o­gy but the line­up of oth­er New York ad-tech angels is impres­sive:  they include App­Nexus founder Bri­an O’Kelley and Dou­bleClick CEO David Rosen­blatt, who had already pitched $1.8 mil­lion in the startup’s first fund­ing round in 2011. Curent esti­mates indi­cate that Tapad is now worth over $140 million.

Cross plat­form intelligence

Tapad doesn’t just drop cook­ies onto a brows­er: for Apple devices, they only work dur­ing a ses­sion any­way. It uses oth­er sig­nals like the net­work ID the device is using and its own unique sig­na­ture; when it sees an Android device vis­it a web­site and then use an app from the same WiFi net­work with­in a few min­utes of each oth­er, it fig­ures that the user is very like­ly the same person.

It aims to pin­point users not through per­son­al­ly iden­ti­fi­able infor­ma­tion but by what device they’re using, retar­get­ing some­one who’s vis­it­ed a mobile web­site or opened an app when they reap­pear some­where else.

Accord­ing to Traas­d­hal, the results are not to be scoffed at: click­through improve­ments are sim­i­lar to retar­get­ing results online and can lift the num­ber up by 50 to 150 per cent.