ToFu is the first stage of the 3 stage sales funnel used by sales and marketing professionals to segment their leads, nurture them and ultimately sell to them. ToFu is an abbreviation for Top of the Funnel. At this stage, sales professionals and marketers think about getting a large volume of leads and not about selling to them. However, this does not mean that these leads are not relevant or they are not coming from among the target audience. It simply means that the focus is not on selling them the product or service at this very stage. At the top of the funnel or ToFu, the idea is to give out relevant information to the lead and address their need, problem or any questions that they have.
The advertisements of any product or service that you have only started seeing recently or have seen only a few times are running in the ToFu stage. Those ads are an attempt to inform you about the product or service or bring attention to any of your issues, problems, needs or questions. By doing this, the company is simply trying to make a statement that they have what you want so you consider purchasing their product or service to solve your problem.