Conventional wisdom has it that Microsoft takes three attempts to get a new product right. The average time for a new mobile segment seems to be eight years.
Mobile data, on every operator's radar since GPRS arrived eight years ago, is only now filling up network pipes. Location-based services have been in the pipeline a similar length of time. We're now at just the first stage - decent maps on the handset - but none of the other apps.
Mobile TV was hyped through the roof a couple of years ago, and nowadays it barely rates a mention at industry events.
The same applies to another much-blogged concept that has been kicking around since the start of the decade: mobile advertising.
As the world's most popular electronic device, mobile is a natural advertising platform; it's always-connected and always with the user, who has a billing relationship with the operator.
Yet it's ironic that one of the obstacles is the lack of information available to advertisers.
The mobile industry body, the GSMA, has been running a trial with UK operators to tackle this. They've been trying to figure out metrics to measure the effectiveness of mobile ads and were supposed to come up with a 'proof of concept' by year-end.
So far, no sign of that, and even with that solved, mobile advertising suffers from plenty of other shortcomings.
Pushkar Sane, a general manager at marketing firm Starcom Mediavest, cited a few at the Mobile Asia Congress last month: in particular that mobile ads are sold in silos, unconnected from other advertising, and that operators can measure eyeballs and clicks but not user intentions - how likely they are to buy, read or download content‾
Sane also argues that operators will have to choose between making money from ads - where they market their services for free - or increase revenue from value-added services. His view is they can't have both. Operators will surely dispute this.
All of which helps to explain the absence of mobile ads.
But the good news is that customers are much more accepting of the idea of ad-supported mobile content.
Mobile ad boosters have been saying that for years, I know, but there is credible proof, courtesy of the Annenberg Center for Digital Media. The center has led a massive worldwide survey on household digital media usage over the past eight years, with panels in some 30 countries of 2,000 people each.
Director Jeffrey Cole says in the coming years most media will get smaller: that is, we'll see smaller aggregate sales of movies, digital music and newspapers.
But the one medium that will grow is TV.
'Our work shows conclusively - and I don't use the word 'conclusive' very often - that people will watch television on small screens in their pockets. Not just short clips, but 30-minute shows, sometimes in ten or 12 parts,' he told the Monaco Media Forum in October.