Priceline, one of the US's leading e-commerce internet sites, is launching in the UK with its first £2m online ad campaign.
The campaign, part of its £10m launch budget, asks shoppers to "Name your own price" for goods and services.
The ads will launch this month and run to January promoting low-cost airline tickets, hotels, rental cars and long-distance phone calls.
Organic, the online advertising and marketing firm, will create banner advertising, sponsorship and email marketing for the site.
It will also explore partnerships with other sites to enable them to sell Priceline's products and services direct to their customers.
John Baker, managing director of Organic's London office, said: "Priceline has an extremely exciting proposition, which has already proved popular in the States, and we will be looking to replicate this in the UK.
"We have a very strong background in delivering online campaigns and are continually exploring new opportunities to help clients maximise the advertising opportunities offered by the internet."
The US site now has 8m users.
Priceline Europe is a joint venture between Priceline.com - the US firm once valued at more than £12bn but now worth less than £700,000 - and venture capital firm General Atlantic Partners.
It made headlines earlier this year when it appointed Dennis Malamatinas, the boss of Burger King, as its chief executive officer.
The company has patented its own internet pricing system allowing web users to type in the price they want to pay for goods and services.
Organic's clients include DaimlerChrysler, BT, Tommy Hilfiger and Blockbuster. It has offices in the US, Canada, Asia, Europe and Latin America.