To be an also-ran is to be remembered only as a trivia answer.
Also-ran is a normally derogatory remark concerning some competition, including political elections, and the folks/participating items who were not either important or interesting enough to commit to memory.
A quick example of this can be found during the Oscars. In a typical year, there are one or two outstanding frontrunners and a couple of other films which many folks have either not heard of or wouldn't be interested in seeing. You can read into that as you will. Most folks can remember when the Lord of the Rings won, but can an average person name two of the other films that were nominated? When Crash won, beating out Brokeback Mountain, both movies were remembered -- Crash as the winner and Brokeback Mountain as 'that gay cowboy flick'. What about the other films in the category? They were also-rans.
Does that take away from the other participants in the competition? Perhaps, but it is human nature to focus on the unusual or winning entrants. The other participants do get the honor of having at least tried to win, which in this current age of apathy is worthy of rememberance, even if only as a response to a Trivial Pursuit® question.
liveforever notes that "also-ran" is originally a term from horse racing.
TenMinJoe concurs, and offers an example: "Red Rum won the race; Moby Dobs also ran." | 
