From what I could find; in the end it comes down to a chart manager. The Billboard wiki page mentions the following: "What separates the charts is which stations and stores are used; each musical genre has a core audience or retail group. Each genre's department at Billboard is headed up by a chart manager, who makes these ...
Wikipedia's page on the Billboard 200 has a list of albums that spent the most weeks (not necessarily consecutively) on the chart:
Most weeks on the chart
Note that totals are for the main albums chart only, catalog chart
totals are not factored in.
(892 weeks) The Dark Side of the Moon – Pink Floyd
(490 weeks) Johnny's Greatest Hits – Johnny Mathis
A lot of the subjects you listed tend to be related to love in some way, as love as a subject spans a large range of emotions. If you want to write an angry song, you can write about love. Sad? Yup, love. Happy? Yep. Almost any emotion that music can express can be related to love.
Another possible reason is that there are a few very specific songwriters ...
The "hot" trackers try to measure full exposure of the song through different channels, buy aggregating data from radio airplay, sales, and streaming.
Radio exposure is measured by a subjective concept of "audience impressions" (quoting from Billboard's own site). Normally this would be evaluated
by using marketing measurement methods, i.e. inquiry of a ...