Do many people use the ELL?

Maybe. It is probably the same as District sunday services from Upminster to Aldgate East (I've thinked that nobody used them ) It would be scraped if it hadn't made some profits

But it's an excellent way of getting across the Thames if you have no car....

When I used the line a few times a couple of months ago, it was quite decently loaded. This was off-peak around early afternoon.

Ikar, as you were informed when you mentioned those services, they do carry people. They are not run to make a profit - individual trains are not run for that purpose on LU. You were also informed as to the reasons they run. Given that it was a few weeks ago now, and given that the thread is now missing, I will understand how you may have forgotten everything that was said.

I have only ever been on the line twice!

I understand it is quite well used in the peak hours, and some people walk from Shoreditch into the city rather then change to the crowded DLR or District.

Wapping is my second nearest station after Tower Hill so I use the ELL a fair bit. My observations during the morning peak would echo adw's comment; there's a lot of commuters out there that take a northbound service from Wapping or Shadwell and change for a w/b H&C / District line @ Whitechapel to avoid the ridiculously long walk from the DLR platforms and the Central line platforms at Bank. Both my flatmates use this route as an alternative and find it a) cooler, b) quieter and c) doesn't require the stair-riddled hike @ Bank. The other poignant thing I tend to notice is (as Phil pointed out) the amount of pedestrians south of the river that take the ELL to Wapping then either walk or hop on the D3 / 100 bus to Canary Wharf or the City respectively to get to work.