That has been pretty good for the piggy-backers themselves. They pay wholesale network charges of around £3-£5 a month and pull in average revenue per user of £10 a month, according to Enders Analysis. But for the old-school telecoms, the surge of 150 new entrants into low-cost mobile has been a mixed blessing. Yes, they get to squeeze cash from unused capacity on their networks. But where MVNOs and cheapie sub-brands once targeted consumers who would not have signed up to pricier subscriptions, now even richer consumers might be tempted to decamp.