<s>
Behavioral	B-Protocol
retargeting	I-Protocol
(	O
also	O
known	O
as	O
behavioral	B-Protocol
remarketing	I-Protocol
,	O
or	O
simply	O
,	O
retargeting	O
)	O
is	O
a	O
form	O
of	O
online	O
targeted	O
advertising	O
by	O
which	O
online	O
advertising	O
is	O
targeted	O
to	O
consumers	O
based	O
on	O
their	O
previous	O
internet	O
behaviour	O
.	O
</s>
<s>
Retargeting	O
tags	B-Protocol
online	O
users	O
by	O
including	O
a	O
pixel	B-Protocol
within	O
the	O
target	O
webpage	O
or	O
email	O
,	O
which	O
sets	O
a	O
cookie	B-Application
in	O
the	O
user	O
's	O
browser	O
.	O
</s>
<s>
Once	O
the	O
cookie	B-Application
is	O
set	O
,	O
the	O
advertiser	O
is	O
able	O
to	O
show	O
ads	O
(	O
often	O
display	O
ads	O
)	O
to	O
that	O
user	O
elsewhere	O
on	O
the	O
internet	O
via	O
an	O
ad	O
exchange	O
.	O
</s>
<s>
Dynamic	B-Protocol
creative	I-Protocol
(	O
also	O
known	O
as	O
personalized	O
retargeting	O
)	O
,	O
allows	O
an	O
advertiser	O
to	O
display	O
a	O
banner	O
created	O
on-the-fly	O
for	O
a	O
particular	O
consumer	O
based	O
on	O
specific	O
pages	O
that	O
they	O
viewed	O
.	O
</s>
<s>
Later	O
,	O
ads	O
showing	O
the	O
product	O
of	O
interest	O
can	O
be	O
custom-linked	O
to	O
point	O
back	O
into	O
the	O
order	B-Application
system	I-Application
.	O
</s>
<s>
While	O
all	O
retargeting	O
depends	O
on	O
setting	O
cookies	B-Application
in	O
a	O
user	O
's	O
browser	O
,	O
there	O
are	O
several	O
different	O
methods	O
of	O
doing	O
this	O
:	O
</s>
<s>
Instead	O
,	O
providers	O
rely	O
upon	O
data	O
gathered	O
from	O
cookies	B-Application
that	O
are	O
placed	O
on	O
a	O
consumer	O
's	O
browser	O
by	O
the	O
websites	O
they	O
visit	O
.	O
</s>
<s>
In	O
the	O
EU	O
,	O
the	O
2002	O
ePrivacy	O
Directive	O
and	O
its	O
2009	O
revision	O
require	O
opt-in	O
consent	O
for	O
the	O
use	O
of	O
cookies	B-Application
and	O
stipulate	O
that	O
users	O
must	O
be	O
given	O
the	O
option	O
of	O
opting	O
out	O
.	O
</s>
