Ours was on for a month with no viewings and I went into the agent to ask what feedback they were getting on it from their clients who had decided not to view it from the details.
Turned out they hadn't shown anybody any details, because they claimed we did not have the legally required energy report bit done yet. It had been done and it had been sent to them on the day we signed on the market with them.
It was there cock-up, but they tried very hard to blame it on us/energy report company.
They hadn't even put the picture in the window. There were photo's on the internet, but no written description.
I was really annoyed. I worked in an estate agents office for six years and I'd have been given a formal warning for leaving a house un-marketed for a month.
When the details were ready we had a viewing within the week and the man said he had seen the sign up and gone into the office to arrange a viewing and been told that they thought we had taken it back off the market because they didn't have any details to give out.
I was not happy. So I asked them to do a door-to-door mail drop and a mail out and they put our house in the paper for four weeks in a row because of all the mistakes.
First viewer turned out to be a nutcase hard work, but he bought the house.
If your agent is not keeping in touch with you (mine didn't) then I would recommend that you call them at least every other day to ask what is going on.
If your house is on Rightmove they can tell you how many people have viewed it on the internet and how that compares to others in the area and they should be able to tell you how many people they have given or sent the details to and what those people said about it and why they decided not to come and view.