What is a "success"?
One "Success" equals 13.8 "Merits". If a Power owes you a "Favour" and you have at least 46,000 "Merits", you can convert "Merits" into "Success", trade it for "Favour" at an exchange rate of 0.3333333333333 and fast-track your "Command Capital" bonus multiplier, up to the "Power Ethos Upper Bound" for your nearest "Command System".
A moment's thought will reveal that "Expansion" follows "Success" using the following equation...

But, of course, we all knew that.