This is a though one. There is spam and there is spam, and it's hard to say exactly where these examples fit in. Personally I think posting dozens of memes a day is a lot worse than what booking.com does, but neither really add value to the platform.
What's more interesting to me is why a whale like @hendrikdegrote upvotes those booking.com posts..
I think @hendrikdegrote has been absentee voting for a bit. Last resteem or comment is 2 months old.