Google appears to be testing a financial comparison site in the UK, which allows you to choose between different credit cards depending on a number of factors. Some users, when searching for credit cards, are being shown adverts for the service and the option to click through.
They're then presented with a chart displaying a variety of credit cards and allowing you to filter by your age, your household income, your credit score and a few other factors. You can also choose to search by introductory balance transfer rate, by introductory purchase rate, or by the typical APR that you'll get.
Google makes money from this by getting referral fees from people who click through and actually apply for the card. However, as the company hasn't made any fanfare out of it, it's likely that this is just a test - similar to its test of a mortgage comparison offering in the USA last year.
If you'd like to give it a go, you can click directly to the page at google.com/comparisonads/ukcredit.