Ad spend

Ad spend is the bill from Meta, Google, TikTok, Taboola and other traffic sources. For an arbitrageur it plays the role that cost of goods plays for a shop: it is what is bought in order to have something to sell. In company accounts it appears as traffic acquisition cost (TAC).

Because revenue and spend are close in size, small errors in counting spend distort everything. Three are common. Platform dashboards and a tracker can disagree, so the invoice is the reference. Spend may be in a different currency from revenue, adding exchange costs. And taxes, agency fees and payment charges are often left out of the campaign view even though they are real.

Spend also has a timing dimension. It leaves the bank quickly, while revenue arrives on net payment terms, creating the cash-flow float. And some of it is deliberately "wasted": tests of new ads and keywords that mostly fail are the research budget of the business. A realistic plan sets aside a share of spend for testing and does not count on it to be profitable.

An example

Say the dashboard shows $10,000 of spend. Add a 4% agency fee ($400) and $150 of card and currency charges: true ad spend is $10,550. Against $12,000 of final revenue, profit is $1,450, not $2,000.