Only people who don't know that task will use a faucet where you claim 20-25 satoshis per captcha.
Can you tell me a little bit more about what mrai is and where you are completing catpchas for it. I am interested in checking that out?
It is RaiBlocks, official thread, https://bitcointalksearch.org/topic/annxrbcryptocurrencys-killer-app-raiblocks-micropayments-1381323
Their faucet, https://raiblockscommunity.net/faucet/
They are going to implement a new faucet rule from tomorrow, "Distribution will be performed hourly, but only top 60 accounts will get paid. Non-top 60 accounts will cumulate claims until will be top 60 in next distributions."
I do not think you can claim continuously from their faucet without any time limitation.
XRB price has increased a bit in the last few months, currently around 900 satoshis and I think that is why they are implementing top 60 feature. They are not listed on any exchange, XRB trading thread, https://bitcointalksearch.org/topic/raiblocks-raiblocks-trading-thread-1422828
Their faucet does not have any referral feature or something like that, a few years ago bitcoin adoption depended on faucets to some extent, mrai is doing the same thing and their increasing price shows it is a success.
I work via this service offer https://bitcointalksearch.org/topic/best-offer-solving-raiblocks-captchas-solothe-end-1763368
I'm not the owner of mrai account, I receive a code that I use to complete mrais, the account owner is credited, he shares many codes with everyone who wants to work for him. So, he sells the mrai we completed for the best price, 90% of profit comes for us and he keeps 10% of profit with him, it's a fair deal. You can also choose for how much you want he sells your mrai.