Wonga.com\'s corporate style is unremittingly cheerful. Apply for one of their online loans and, provided your application is successful, you\'ll get a series of happy messages, dotted with upbeat exclamation marks, giving an account of the progress of the loan. \"Great news! The money will be with you in a jiffy.\" And a little later: \"Great news! We can confirm £100.00 has just left Wonga and is winging its way to your bank account at the speed of light (well, extremely fast anyway).\" Pay it back, and you\'ll receive a grateful text that tells you: \"Thanks! We\'ve just collected our Wonga repayment without a hitch and we\'re all smiles.\" The company\'s TV and radio ads have a similarly light-hearted feel. On television, a trio of gurning puppet pensioners dance to house music and explain the attractions of the Wonga model. The company\'s other key advertising message is transparency, but these advertisements make no mention of the \"representative\" 4,214% APR applied to loans. In the four years since the company launched, the business has soared and a total of around 3.5m short-term online loans have been made; the average loan is £260 and the maximum is £1,000, initially for a maximum of 30 days. Wonga\'s advertising spend has grown from approximately £22,000 in 2009 to £16m in 2011, according to the analysts AC Nielson MMS, and the brand is currently plastered over London\'s buses and the shirts of Blackpool and Heart of Midlothian football teams. Wonga describes its concept as a convenient service for an internet-savvy group of consumers, the Facebook generation, people who are used to getting things fast, who feel \"disenfranchised\" from the traditional banking system. Loans can be made quickly on most smartphones and the money is often delivered to bank accounts in minutes. Staff believe that in time their services will have the same revolutionary impact on banking as Amazon had on the book industry. Wonga argues that its success stems from a fast, hi-tech service, not previously available. Critics says it is down to extending expensive credit – at an interest rate of 1% a day – to people who are unable to get money through conventional, cheaper avenues. There is a huge disconnect between the Wonga management\'s view of these services and the view from beyond its headquarters, where campaigners against the rapidly growing payday loan industry describe them as \"immoral and unjust\" and \"legal loan sharks\". There is an equally big gulf between the way it portrays its average customer (\"young professionals who are web-savvy, fully-banked, have access to mainstream credit and a regular income\"), 95% of whom, according to its customer surveys, feel \"satisfied\" with the service, and the characterisation offered by debt counsellors and MPs, who are seeing increasing numbers of customers winding up in financial trouble as a result of taking out payday loans. Citizens Advice reports a fourfold increase over two years in the number of people with payday-loan-related problems. Last week, the Office of Fair Trading launched a review of the payday lending sector, looking at all the companies offering these short-term unsecured loans, which are usually repaid on the customer\'s next payday, in response to concerns that \"some payday lenders are taking advantage of people in financial difficulty\" and not meeting \"guidance on irresponsible lending\". The OFT said it aimed to drive out companies that are not fit to hold consumer credit licences. Wonga does not expect to be one of the companies driven out of the market, and the company\'s advertising strategy tries to set Wonga aside from the myriad of evocatively named rival online companies that offer money if you Google payday loans: Kwikcash, Loans for Women, QuickQuid, Toothfairy, Payday UK, Payday Express, GetCashToday.co.uk and Peachy (which has a \"representative\" APR of 16,381%).