A me-too product is one a company begins to sell only after it has seen that other companies are already doing well with the same kind of thing. It is not a proud word. If a drink or a phone becomes a hit, and six other companies quickly sell almost the same thing with a new logo, those later products are me-too products. People in business use it to show disapproval: the company did not invent much, and did not take the first risk; it just followed. You can also hear me-too about films, songs, or apps that copy a success. The tone is informal even when the speaker is in a meeting. Though actually, copying a successful thing is how a lot of shops work, so the phrase is a judgment, not a law. This older business meaning is also easy to mix up with a later use of the same little words — that later use is a different story.