How can I tell which internet service providers won’t impose limits on the amount of data I download before I sign on their dotted line?

According to a survey taken last year by ISPA, the trade association for internet service providers, only 20% of new broadband customers take any notice of potential usage restrictions. This may be because many ISPs loudly proclaim their service as unlimited – or, commonly, unlimited* – while burying details of any limits, or caps, deep within the small print. “I’m astonished that the advertising regulators seem to still allow this,” writes Ben Lane, and indeed most of this week’s correspondents are more critical of misleading advertising than the downloading restrictions themselves.

Although data clearly isn’t a finite resource, the more of it we want, the more it costs the ISPs to provide it, and we’re slowly becoming aware that the more we pay, the more we get. “I voluntarily chose a capped service,” writes Jo Mackereth, “because it’s cheaper, and I don’t use BitTorrent, or YouTube, or whatever it is that young people do.” Indeed, many ISPs can only sustain their business models because of users like Jo, who surf irregularly and perhaps check their email twice a day. But, as new internet applications take advantage of higher connection speeds, we’re all slowly slipping into the “heavy user” bracket – even without getting involved in potentially dubious practices such as file-sharing. Innocuous services such as the BBC website’s “Listen Again” feature, or using internet telephony to make cheap international calls – they can all add substantially to data consumption. Part of the problem is that barely anyone – including me – has any idea of how much data they download in one month, because visible metering is rarely offered by ISPs. “I was amazed when I discovered that I shifted nearly 1Gb of data during one day playing games online,” writes Nick Sefton. Some panic-stricken ISPs, seemingly unprepared for intensive, legal usage of their service, are responding by substantially reducing the connection speed of heavy users, and, in some cases, terminating their accounts. The “offenders”, of course, are furious, having signed up to what they understood to be an unlimited service.

As a rule, if it’s cheap – under £20 per month – it certainly won’t be unlimited. And if it’s more expensive, it’s probably still capped to some extent. “My service with Zen Internet is quite expensive – £34.99 / month – but it’s very reliable,” writes Jon Deeks. “And I’ve no idea how I’d ever reach their 50Gb monthly limit,” he adds. Jon’s conclusion isn’t futureproof, but 50Gb could certainly be considered generous in the current climate. But always check the small print, as some ISPs have a more miserly idea of what constitutes “fair usage”.

Next week’s question comes from Louise Stannard: “Geeks seem to get very worked up over something called Web 2.0 – but what is it actually supposed to be? And should I care?”