By 'additional services' (!!) I assume you mean being flexible in ways that other childcare providers can't?
I think this is absolutely the right approach.
Speaking as a mum who used a childminder and also a nursery, I would say the things that are most helpful are:
Being able to fit around those awkward times, such as when a child starts school in reception and is on part time days. That can be a really tricky time, as the nursery place no longer exists, but normal 'before and after' school doesn't fit either. Also, if you can offer 'walk to school' service for older kids, that's helpful too. Another thing to think about is that nurseries usually charge full rate all year round, whether the parent needs it or not, so if you are willing to negotiate, say, half pay, for times the parent isn't working, that will give you the edge over other providers. I have some teacher friends who use childminders who offer term time only places, which obviously saves them a lot of money. I know some nurseries now do this, to attract teachers, but see what the score is in your area. Think about whether there are any activities you can provide which will make you a really attractive option.
Ultimately, parents will pay for the best kind of care they can afford, and may have a preference for nursery, particularly for slightly older children, but for parents who don't have a fixed preference, and will shop around, you need to place yourself carefully in the market. I think once you've established yourself, it's all about reputation anyway - if parents recommend you, you could find yourself with a waiting list.