Preparations for the London Olympics had appeared to be going rather well. The massive building programme transforming east London is largely on time and on budget – in itself a minor miracle – and persuading people to buy tickets proved the least of the challenges. Notwithstanding the row over the sponsorship deal with Dow Chemical, glitches in the ticketing website, and a doubling of security numbers, progress has been surprisingly smooth. Even the "Isles of Wonder" opening ceremony, inspired by everything from The Tempest to the NHS, has potential.

If only that were the whole story. But efforts to ensure that the benefits of hosting the Games are worth the staggering cost are not just a matter of showbiz, tickets and building contractors. There is also the economic impact, as any number of tourism-reliant businesses will attest. It is a matter of concern, therefore, that the London Organising Committee (Locog) not only overbooked a staggering 120,000 hotel room nights over the course of the Games, but, by returning them to the open market, is wreaking even greater havoc. Locog says it is honouring the deal with hoteliers and there is still time for the rooms to be sold. But industry insiders are less complacent, predicting huge loss of income, and even lost jobs, as room rates slump in response to the sudden surge in supply.

Nor is the hotel room debacle the only threat to the legacy of London 2012. Although six out of the eight venues now have a future beyond August, the likelihood of signing a tenant for the £468m main stadium before the Games begin is looking slimmer by the day. The latest far from promising twist is that front-runner West Ham FC is so frustrated with the Olympic Park Legacy Company that it is reviewing its options ahead of this week's deadline for bids.

Between now and July, anticipation of the impending Games will do much to distract attention. But once the medals have been collected and the athletes have gone home, the cost/benefit analysis will come back into focus. Neither Locog nor the OPLC are helping ensure that the balance is firmly in favour, which is where it should be.