Why do papers have many Mendeley readers but few Scopus-indexed citations and vice versa?

Mike Thelwall. Why do papers have many Mendeley readers but few Scopus-indexed citations and vice versa?. JOLIS, 49(2):144-151, 2017. [doi]

@article{Thelwall17-5,
  title = {Why do papers have many Mendeley readers but few Scopus-indexed citations and vice versa?},
  author = {Mike Thelwall},
  year = {2017},
  doi = {10.1177/0961000615594867},
  url = {https://doi.org/10.1177/0961000615594867},
  researchr = {https://researchr.org/publication/Thelwall17-5},
  cites = {0},
  citedby = {0},
  journal = {JOLIS},
  volume = {49},
  number = {2},
  pages = {144-151},
}