Hi Roy,
7 in two and a half hours sounds good, the general thought is 1 in 10 people you speak to but that covers all kinds of areas. The key to consistant results is choosing your areas carefully and always having a plan b if your first choice not going well. My best day this year worked out at 1 in 3 which is unusual but I always tend to better than the 1 in 10 but that works as a good baseline so if you speak to 100 people which would be hard, you should come out with 10 jobs making it a worhwhile day....
Hope that makes sense....