TfL brings a strong search marketing game to print adverts

TfL have an advert up at Holborn tube promoting their weekend tube line information service.
Tfl
I noticed in the text at the bottom that they then encourage the audience to use a particular search term so they can find the content they want.
TFL
This has probably made reduced the cost of the campaign as only organic search work is needed and allowed the SEO work to be more focused.