I think it can also depend on the consultant you work with. I joined 2 agencies last year. The consultant at one of them was hopeless. She left after one term and was replaced by someone much more proactive who offered me a fair bit of work. However, by then I was getting enough work through the other agency so had to decline much of the work offered. I don't want longer term roles anymore, but find that doing day to day seems to be the way into longer term roles as once a school gets to know you, you are more likely to be offered maternity / long-term sickness cover roles.