The old guy always has it.
Stereotyping, while not a good thing in most other aspects of life, has a definite, acceptable place in poker. In fact, when you first sit down at a table, you need to use any and all clues at your disposal to start putting other players on hand ranges. This includes--gasp--the age, race, gender, clothing, body art, hygiene, and any and all other external factors the opp exhibits. The guy is eighty years old and betting strong on all three streets? It's more likely he has it than not. The guy is twenty with a hoodie and sunglasses? Now it's much less likely. This kind of stereotyping is valid online, too. The player has a hip poker-slang screen name like DonkeyBaller, complete with a bunch of site accolades and awards attached to his avatar? He's probably going to play LAggier than someone named JoansGrandDad1954. Stereotyping is just another valid tool to categorize opponents when you first sit down. Then you can start the process of refining your reads with actual notes, tells, betting, and other indicators.
All-in for now...