Time-to-first-campaign, or TTFC, measures how long it takes from signing an ABM platform to having a real campaign live against real accounts. It captures implementation, integration, list building and content production, and it is the clearest early indicator of whether a programme will return anything in its first year.
Because an annual contract that takes five months to activate is a seven-month contract sold at twelve months' price. TTFC is the number that converts an implementation timeline into the thing finance actually cares about, which is how much of the term you get to use.
Rarely the software. Usually the sequence in front of it: agreeing the target account list, getting CRM data clean enough to segment on, and producing content per segment. Content is almost always the constraint, and it is the step buyers most often assume the platform handles.
Not how long implementation takes, but how long until a campaign is live, and what has to be true on your side for that to happen. The second half of the question is where the honest answers live.
Narrow the first campaign. One tier, one segment, one channel, shipped in weeks, beats a complete programme designed for six months. The first campaign's job is to prove the pipes work. See lean ABM for running the whole programme that way.