Demon Internet is a British Internet Service Provider. It was one of the earliest ISPs, starting on 1 June 1992 from an idea on CIX. The branch in the Netherlands started in 1996.
Its first service was dialup IP, combined with access to mail and news servers. This was priced at £10 a month (£11.75 including TAX), or as it was described in the sales literature, a 'tenner a month'. They still offer this service at the same price today, but more customers today use the surftime and ADSL packages.
In 1998 it was bought by privatised utility company Scottish Power (now rebranded as Thus).