Find huge amount. Say "if only X%" (usually 1% or something else low) then increase of 1%*huge amount which is still a huge amount!
Somehow the argument of "if only X%" is meant to avoid the need to prove that you can, in fact, do X%.
1% of extra revenue is hard. 1% time save across the board is hard. If you claim 1%, you better have some strong arguments as to how you can achieve 1%, not do "handwavy do something with synergy or extra information - even if we just get 1% which is a low number, 1% of something huge is still huge. We think we can do more than 1%!".
It is almost as pervasive as hindsight arguments that ignore risk costs. "I put all my money on black at the roulette table and my business is up 100% in the last year - I will bring huge wins to you".