Is fanservice considered good in anime? I have watched the first episode of Neon Genesis Evangelion and at the end, after the credits, there was a short teaser of the next episode, ended with the sentence:

Tune in next time for lots more fan service!

I have watched much more American TV shows and movies than anime, so for me, the word &quot;fanservice&quot; has more bad associations, like some unnecessary things, not connected to the plot. So if fanservice is mentioned in a teaser, does it mean something else in anime, or do people watching anime like fanservice rather than looking down on it?
All though I don't think we really can answer the &quot;do people enjoy watching fanservice&quot; part of the question. As this is left to the opinion of the viewer, lets get into what 'fan-service' entails in anime.
Your definition of &quot;something unnecessary
and &quot;not connected to the plot&quot;, except when talking about watching it for the plot (definition may be considered nsfw, look it up at your own discretion) is pretty accurate.
Fanservice content's direct intention is to please the audience, which often leads to content of a sexual nature in anime targeting the Shounen and sometimes Shoujo demographic.
These scenario's can come forth through a range of causes. In-universe reasons range from innocence of the character, to accidental walk ins. But it is not uncommon to have scripted 'beach episodes' or 'bathing scenes' where either implied nudity or absurdly small bikini's are featured as a form of fan-service.
Hence the fan service mentioned in the teaser implies that more such scene's will be shown. However, by my recollection of the series, no actual body parts are shown in those scene's. With the exception of the directors cut version, which did feature nipples on certain characters.