In the kids vertical, generally, on average, subs convert at 1 to 1000 views. If you have awesome content, you might get 1 sub at 200-500 views. If your content sucks, you'll get 1 sub at 2000-5000 views. This is my experience in this vertical. Each vertical will be different. Do your own research to determine the low, high and mid conversion ranges.
Now, if you run Adwords, for 1000 views ($10 at 1 cent CPC), you might get 2-5, perhaps 7 subs. Conversions are higher because Adwords is very much targeted.
Depending on your costs of sub acquisition, it may be more worthwhile to do Adwords.
For example, if you spend 10 hours of online activity to gain 10 subs, at minimum wage of $10/hour, that's $100 for 10 subs, or $10 per sub. If you run Adwords, you can get a sub at $2-$5 (for example). That may be the route for you to go if you are doing this as a business. If doing this as a hobby, ignore all the above, and have fun!