If I recall correctly, they released a single called " Get on your boots" not too long ago. How did that work out in terms of keeping them relevant ? 
Very true

.
But seriously, if they want to stay "relevant", or to become "relevant" again, they need to start appealling to a wider audience, which means writing and releasing strong singles that chart well.
The sad thing is that U2 have been losing their relevancy for the past decade; that is, longer than a lot of people on this forum have been fans. Also, this isn't the first time that the relevancy issue has been mentioned by the band. I remember one of the members saying in an interview during the HTDAAB campaign (can't remember who, or where it was published/aired) that the band were finding it increasingly difficult to stay relevant in the current climate. It was also mentioned after "Rattle & Hum" and again shortly after NLOTH was released. (But not in that order!!

)
"ATYCLB" had one ripper of a single (in BD), and three perfectly adequate follow-ups which all charted well. "Bomb" had two strong singles in COBL and SYCMIOYO, and the record buying public (in this neck of the woods, at least) agreed. NLOTH had, in my opinion, none. And the record buying public also agreed.
How many strong singles did JT and AB have? The singles off these albums are instantly recognizable to those who consider themselves fans of music. But the singles from the last three albums (with the exception of Beautiful Day), are not as iconic. There's a pattern emerging here, and it's becoming more apparent with each album that is released.
I think they are (or were) more of a singles band than they would care to admit.
.
My 2 cents.
