BT's fibre broadband service has been rolled out to more than three million premises around the UK.
However, of those, just 38,000 are using the telecom company's own Infinity service, with the remainder using fibre services offered by other ISPs that pay BT to use the infrastructure.
Ian Livingstone revealed the figures during the telecom company's financial results announcement. Livingstone also said some 4,000 Brits were taking up the Infinity service every week.
BT Infinity, which was launched in January this year, offers download speeds of up to 40Mbps and upstream speeds up to 10Mbps, with prices starting from £19.99 per month.
Furthermore, the company's TV-on-demand service, BT Vision, now has more than half a million customers. However, less than 10 percent have taken up its subscription Sky Sports service, which was made available in August.
BT revealed its pre-tax profits were £496m, which is 13 percent up on last year, and an increase on predicted profits.
The news comes as BT revealed it will be rolling out the BBC iPlayer to its half a million BT Vision customers over the next five months.