impact outcomes only as spoilers, but some might "succeed" (short or long run) as more than vanity projects in that they can exert pressure on the parties if they find a big enough audience. Or they can be imported into a party and take over, with Trump being the example of this. If he ran in 1996 or 2000 he runs as a Reform party candidate, but in 2016 he packages prior Reform candidates Perot and Buchanan (plus more celebrity and charisma) in the R primary, wins it, and he becomes the dominant force in that party.

A "no labels" might similarly gain traction building from the ground up, then years later import itself into an existing party if there was enough demand for it. It could only function as a spoiler in third party form now, there's not enough demand to import it and win now, but in 15 years there might be.