Precise term for a sort of social pressure Context: It is known that some pubs and the like usually offer free drinks for females. The owner of the place expects then that more males will come and pay for a drink for themselves because a considerable amount of females are already there, so that the payout for the owner is positive. To put another example, in some casinos, people get paid to play slots machine so that the sound of it and seen people getting money from it encourages other people to play slots machine as well.


  Is there a precise term for that effect/social behavior? 


I apologize if the question is not too narrow and I will happily make it more precise if it is required. Thank you (and happy new year!).
The first practice (sometimes called ladies' nights or similar) is a form of sex-based pricing and is seen by some as a form of commoditization
 (aka commodification) of women. It's illegal in the UK and parts of US.

The casino design part of your question is mostly unrelated, although some casinos surely use even more blatant commodification of women as part of their strategy [for attracting men], such as skimpy outfits for their female employees. The things you ask about such having slots right in your face at the entrance has been (traditionally) considered to be superior to empty entrance lobbies at attracting more bets, but it's not totally clear if that works by peer pressure, exposure or a combination. This type of (heavy) gaming casino design with machines everywhere starting from the entrance is also called Friedman-type after Bill Friedman who wrote a book-size document promoting it.

More recent studies such as Finlay et al. (2009) found however that creating a playground atmosphere is what encourages most bets from most people, simply because they spend more time in the casino. This type of casino design was promoted by Roger Thomas although the playground name for it apparently came from an academic, David Kranes. Interestingly the crowding (of people) in this type of playground casino design is reduced compared to the traditional "gaming" one. Apparently this gets women to bet more than they had planned, but has little effect on men; quoting from the Finlay (2009) study:


  Relative to a densely crowded casino (high information load), a sparsely
  crowded casino (low information load) was more harmful for females who
  reported higher levels of intention to gamble beyond planned levels in the less
  crowded condition. For males, at-risk intention was not affected by crowding.
  For both genders, crowding had no significant impact on restoration and pleasure.
  Tuan (1977) characterized crowding as “an awareness that one is observed”
  (p. 60). A sparsely crowded gambling venue may increase gambling intentions
  among females because they feel unobserved. This release from inhibition is
  not characteristic of males. Loo (1978) indicated that female adults tend to
  react more positively to a dense crowd than do males. Females are more inclined
  to be cooperative which is conducive to a dense crowd. In contrast, males are
  more inclined to be competitive which will be enhanced with a dense crowd. 
  These results suggest that females should be counseled to avoid gambling in
  relative isolation. Note that in the case of crowding, a high information load is
  protective for females.