LTE for heavy mobile broadband users? A paradox

Various presenters at the LTE Summit have said things along the lines of:

- 5% of mobile broadband customers generate 70-80% of traffic (eg the Telenor subscriber downloading 230GB per month over HSPA)
- A few inner-city HSPA cells are overloaded (3 or 4 carriers) while the ones in rural areas are essentially empty
- Most of the traffic comes from PCs or iPhones

But what's certainly not obvious to me is that the 5% of heavy HSPA users suddenly become profitable if you give them LTE instead, especially in expensive new spectrum for 20MHz channels. Why not just give them a femtocell for use at home, implement strict caps, or just get rid of them entirely?

Or that upgrading a few urban "hotspots" to LTE solves all the problems, given the need for everyone to have new LTE devices (you can't really say "only upgrade your dongle if you think you might use it in London W1 some time in the next year")

The only argument for short-term LTE deployment at the moment seems to be around spectrum flexibility, and the option to use thin slivers in refarmed GSM bands, or awkward allocations elsewhere that don't map onto HSPA's 5MHz channels. For most operators, that's unlikely to be an easy business case.