1. They often have too many entries, 5 to 8 is about right, ten is too much.
2. They usually have pretty much everything you expected.
3. You know it’s a list post to attract your attention and little else.
4. You can think of at least one thing the writer left off the list.
5. Before you know it you’ve been sucked in to reading all the entries even though you thought it was a crappy list at point 2.