Based on what I see for some altcoin project in the market the price can be increase by popularity but first its need a good project concept or a good technology inside then next step is the marketing strategy tobe know or popular in the crypto world means both are good for alts project.
Marketing and speculating are the only thing need to have a rally in all these coins and that is happening for a very long time and if that is not the case why we need multiple coins for the same purpose, some are solid coins with special features for privacy and security but there are ton of coins which serves the same purpose and hence in my opinion marketing and speculation is the one boosting the price.