That article pre-dates Starling’s huge ad spend which began around a month ago so doesn’t really reflect their advertising blanket bombing of London.
Monzo has grown much faster than Starling at every stage according to the figures available. There don’t seem to be any figures from Starling after their ad campaign began very recently so perhaps they are adding more than the 120,000 Monzo are currently adding each month? We will have to wait and see. I doubt it though.
There is an ongoing thread now (How do you “sell” Monzo to your friends?) in which Monzo’s marketing team are asking everyone for suggestions regarding their imminent ad campaign which appears to also be huge, including tv ads.
Whoever is growing fastest and whoever is better, it’s exciting times for all of fintech as the market is maturing and these guys are definitely hitting the mainstream now.