This isn't a very technical or sophisticated method but it works for my cohorts and I. When considering a new startup idea or really anything (domain name, features, marketing) we just put all our ideas up on the wall for about a week or two. By the end of the week, whichever idea has been built upon the most (variants or child ideas) is pursued and the others shamelessly forgotten. If no idea gets built upon it means our current work is more fertile than any of the new ones.
Also, #5 struck my attention and echoes the fact that most good "new" ideas are too contrarian for the general public to pick up on and are hardly profitable right off the bat. Some say primordial Google (search) was in this boat but Yahoo had existed since 1995 along with others, hints the next "______"s are easier for people to find because they are fed up with the old system and will type in "______" without spam/flashy ads or "_______" with such and such feature that works. People first need to know what "_______" is to search for it. A fact that spells disaster for truly revolutionary ideas.
Also, #5 struck my attention and echoes the fact that most good "new" ideas are too contrarian for the general public to pick up on and are hardly profitable right off the bat. Some say primordial Google (search) was in this boat but Yahoo had existed since 1995 along with others, hints the next "______"s are easier for people to find because they are fed up with the old system and will type in "______" without spam/flashy ads or "_______" with such and such feature that works. People first need to know what "_______" is to search for it. A fact that spells disaster for truly revolutionary ideas.