(This answer requires a short diversion into the economics of RSSRadio, please bear with me).
RSSRadio allows you to start using it for free, after a time you may find it won't let you add any more subscriptions.
I make my living putting Apps on the App Store®, I feel these are of high quality and I hope you like them. (about me) What this means is that RSSRadio must make a certain amount of money, it makes this from the Ads that you see in the App, and also from the in-app-purchases to remove the Ads.
If I could make enough money from the Ads then I would gladly remove the subscription limit, sadly this isn't possible particularly due to the seasonal nature of Ads. However all is not lost, what I do is give you as many free subscriptions as i can whilst still making the minimum income.
What this means in practice is that in times where ad revenue is high (in the run up to Christmas for instance), then I will raise the free limit and in times where ad revenue is low I will lower the free limit. This limit is on a per country basis, so it does change over the world.
Practically what this means is that the free limit varies, it can never be lower than 3 and it can never be higher than 99. Over time as RSSRadio gains users I have been able to raise this limit and I hope in the future to be able to give as many people as possible a chance to use this high quality Podcasting App at the minimum cost I can.
If you have any comments on this article, or suggestions. As always email me: firstname.lastname@example.org