During the latter half of the twentieth century, most off-street prostitution was advertised locally using
personal advertisements in the printed press or postcards in the windows of commercial premises such as
newsagent's shops. As direct references to prostitution were not acceptable, the advertisements were carefully worded with euphemistic terms such as
large chest for sale. In larger cities,
tart cards were placed in
telephone boxes. By the year 2000, the
Internet, and access to it had grown large enough for some in the
sex industry to see it as a marketing tool. As use of the Internet has subsequently grown, so has the use of it by the sex industry. As the majority of local newspapers were members, this ban increased the move towards Internet advertising. Mobile devices such as
smartphones have further increased the use of the Internet both generally and for prostitution websites. In the Netherlands, the Internet had grown in importance by the mid 2010s as a platform for recruiting prostitutes' clients, with
escort workers advertising their mobile telephone numbers online. By that time in the UK, Adultwork and
Punternet had become two of the most popular websites for advertising sex work, and in some parts of the country they had largely replaced brothels and saunas as ways to locate clients. ==Types of websites==