I remember Nano, when they are just starting out they are already popular even though they are not yet on an exchange, IDENA has a huge chance, to get into the big exchange and command a good price, right now they are traded at 125 sats per DNA I think it's very low, once it gets into the exchange if Nano reach $15 on their all-time high, IDENA will be better.
They are popular because of the type of distribution they made, Since Idena mining is a little bit complicated for newcomers it creates an entry barrier that limits the growth of the community.
With an average of 40 new nodes every validation it would be 1,000 nodes in the next 2 months and mining would become more harder and slower. This will create a shortage and the price of OTC will probably increase by that time.