The specific area of an ICO obviously doesn't guarantee success, you need to delve deeper into the specific details. A successful ICO will normally have an innovative solution to an issue that affects a large number of people, that way they instantly have buyers interested. The problem is the copy cats, sometimes it is not always the first one to come up with the solution that corners the market, but one of the following ones that 'improves the improvement'. Tough one, but if you can pick the one with the best solution, you'll be onto a winner.