Lot of times when we do a tech feature, we are not very sure as a techie what business impact it will have. But this is a tech architecture issue which I am sure impacting these products for sure. Here I am talking about PayTM and Amazon Pay and I am just guessing here what impact this would have on them.
So both the wallets have an option to auto recharge the wallet. So you can configure them to recharge by an amount of X if the balance goes below an amount Y. This is a very useful feature as this enables people who use these wallets regularly to have a full wallet always and since you can customise the value of X & Y, you can decide them based on your usage patterns.
The way Amazon Pay works is that as soon as you make a payment which takes amount in your wallet below threshold Y, the recharge by amount X is done immediately and you are ready to roll. They are probably using a pubsub architecture where a listener process is listening on the event Low Wallet Balance and that triggers a recharge.
Now let us see how PayTM works. It appears that it runs a cron job which takes a bunch of users at a fixed time and checks if they have low balance and recharges them. I made a purchase yesterday evening via PayTM which brought my balance below the threshold and it was only today morning that recharge got done.
What this means is that I am more likely to have an under funded wallet for a much longer time on PayTM compared to Amazon Pay. The likelihood of usage of wallet will go down during this phase for sure. A simple approach to use pubsub will ensure a better experience for user.