Security wise it's not the best coin due to the low hashrate, but when you transact in very low amounts it's a great network to use because the transactions are fast and near free.
Exactly, I forgot about microtransactions. DOGE's popularity is also due to the fact that it is the second, after Bitcoin, coin used in faucets, which are very often the first form of use by new users. Also through this, exchanges implement DOGE in the first place, even before DASH and XRP as the main exchange pair. That is why, though the low volume, the DOGE price reacts as one of the first when the sentiments on the market are changing. I also think that thanks to huge community, the price of DOGE will grow much more steadily than Alts, which are only used by whales and speculators.