I believe that's $15M PROFIT per year within a year.
I don't have an abacus, but I just figured it this way:
2.53M per 6 months TIMES TWO = about $5M on an annualized basis.
100% of $5M would be $10M,
200% would be another $5M, making it $15M.
That's running at the rate of "$15M annualized PROFIT" one year from now.
(If they string together just two years of 200% growth, it's $45M per year of not revs but profit. If they do it three years, we're not talking $135M "revs" per year but $135M EARNINGS per year. Who has $135M OPERATING PROFIT per year?)
I believe that was the actual guidance Medium gave.
Even Medium themselves would agree with my $15M-profit-per-year comment above, only they called it "20 Billion Won," which is $16.9M USD.
(My simple math above was off by $1.9M, but close enough we see it's what they actually do mean.)