The honest problem in a first year is that you cannot calculate it properly, because a true figure needs retention data you do not yet have. Anybody producing a confident lifetime value for a nine month old business is extrapolating from very little. What you can do instead is calculate a deliberately conservative version and let it improve as evidence accumulates. Take your average sale, multiply by the number of times a typical customer has bought so far rather than the number you hope they will, and multiply by your gross margin. That last step is the one people skip, and it matters enormously, because you cannot spend revenue on advertising, only the margin left after delivering the work.
An example makes the difference visible. A service priced at four hundred dollars with a fifty percent margin returns two hundred dollars in gross profit on the first sale. If customers typically come back twice, the conservative figure is around six hundred dollars, and it would be reasonable to spend somewhere in the range of one hundred fifty to two hundred dollars acquiring one, depending on how long you can wait to recover it. The same business quoting a lifetime value of twelve hundred dollars because it assumes six purchases has not measured anything. It has made a wish and attached a number to it.
Cash timing matters as much as the total. A customer worth six hundred dollars over three years does not help you pay for advertising this month. The useful companion figure is how long it takes to recover what you spent acquiring them, and for a business without much cash the honest constraint is that acquisition should roughly pay for itself on the first purchase. Businesses that spend against future lifetime value need the runway to survive the gap, which is precisely what a first year business does not have.
Segment it as soon as you have enough customers to see a pattern, because the average conceals the useful information. Nearly every business finds that some type of customer is worth several times another, and the correct response is not to raise the average but to acquire more of the profitable type and stop pursuing the rest. That decision is usually worth more than any improvement to the marketing itself, and it is the same argument for narrowing that shows up whenever you look honestly at where the money actually comes from.