It is effectively advertised by everyone for Elon for near 0 dollars. Launch a rocket (different company) the article will mention Tesla for them. Talk about saving the environment guess who gets mentioned. Talk about power needs, Tesla comes up as cars are becoming a large consumer of electricity, solar, coal, nuke, etc.
His advertising is basically being done for free by companies who do not even really realize it.
A story that I remember from the 80s is that the brought in a consultant to improve sales. Rather than advertising, they opted to add one more hole to their cans. Sales went up 20%.
Starlink? That's consumer-facing.
That being said - I don't think a successful one-time advertising push by a completely new field speaks to the long-term benefits of it once they (presumably) become established.
Besides, the advertising budget of other government contractors/satellite companies is also close to zero.
The better question is "If I ran Pepsi today - would I drastically lower the advertising budget". I'm not sure what my move would be but I don't think looking at short term ROI of TV ads would be informative.