All I Know 'bout summmer hits

Sometimes I don't understand how some songs and artists succeed to stay under the radar.
Without any commercial success.

For example UK band Fenech-Soler is one of those artists. Although they are doing their thing since 2006, they are still commonly unknown band.

And it's not that they have a good style but not one potential hit.
They have both, but I guess luck is also one big, big factor. :)