I don't think it's that popular. I've never seen it or heard anyone talking about it. I've never seen it advertised or heard any references to characters in it. I don't even know if it's pronounced 'it' or 'I.T.' (eye tee). It could be just one that passed me by though. My perception is Friends was very popular in America so I would guess The IT Crowd is not as popular in the UK.

It was what is known as a 'cult' comedy. It had a small but dedicated fan base.