Rich, again, I think it varies by both culture and individuals. For some, it's a means of honoring relatives and acestors. In others, it's a means of honoring saints and other religious figures.
In my family, my wife Michelle had our daughter (technically, my step-daughter) before we met. Her name was Emma Elayna Rose Sabistina--"Emma" was a name she liked, and both "Elayna" and "Rose" are honoring relatives while also names she just thought sounded nice together-"Emma Elayna Rose" just seems to roll off the tongue nicely, especially when she's in trouble.
(Emma's bio-dad wasn't in the picture at the time, which is why she had Michelle's last name.)
When we got married, we decided that both Michelle and Emma would take my last name, but that they would take Michelle's maiden name of "Sabistina" as an additional middle name. This is actually a rapidly growing practice, for women who get married to have their maiden name become either their new (only) middle name, or to have it become an additional middle name. So Michelle became Michelle Lee Sabistina Verkuilen, and Emma became Emma Elayna Rose Sabistina Verkuilen.
When we had our sons, we decided to follow suit on each of them, choosing a "name we like" as the first name, honoring relatives with the first two middle names, having Michelle's maiden name be a third middle name, and then the Verkuilen last name. So that's how Connor Henry Edward Sabistina Verkuilen (Henry is my dad's middle name, Edward is Michelle's dad's middle name) and Adam William Russell Sabistina Verkuilen (William is both my first name and my paternal grandpa's middle name, and Russell is my maternal grandpa's first name) were named.
Bill
p.s. Both Michelle and all the kids frequently skip the "Sabistina" when asked for their full name, unless it's in a situation like court papers. And when you skip the "Sabistina", and look at the initials--I think you'll see why my personal nickname for Connor is "Chevy".