This tip should be taken on board for all your labels content and not just specific to youTube.
One of the key ingredients to keeping your fans coming back is consistency, it's all good promoting your channel and finding new subscribers, however you need to ensure you can maintain your current subscribers.
Keeping your formatting, schedule and content consistent is important as it allows viewers to come back to your channel and be presented with new content, but also content that fits your channel ethos, which is why they originally subscribed.
The formatting of your videos is important as it re-enforces your brand, for example, this may be a 5-second intro at the beginning of your videos.
Consistent uploads are also important, this helps your viewers know what to expect and when to expect it. You may upload a weekly podcast, or upload your latest release sampler to YouTube on or just before the release date. This means they may re-visit your channel as they are looking out for your latest podcast etc.
Regular uploads also help keep the channel fresh so it does not stagnate. When starting the channel, think about if you have the means to create content that will facilitate consistent uploads.