what makes a soft site?

i know that a soft game is basically a high pre-flop % and not alot of raising (debatable, as some may prefer crazy fish over passive fish)

but wondering what makes a poker site have a large number of these good "soft" games. seems alot of fishy traffic may have gravitated to no-limit/shorthanded.

as i had mentioned in other threads, i recently changed from a sports book to party poker. the sports book was pretty soft but the availability of tables was terrible and it seemed like there was a major lack of bonuses. anyhow, i found party poker quite tight at 2/4 (i know others will say there's lots of VPIP > 30% but that's often after a raise, and i don't think it's a high number anyhow, i'd be looking more for 40%+)

this got me thinking what makes a poker site soft. here are some thoughts:

1) doesn't allow multi-tabling. in response, i think i may multi-site poker sites that don't allow multi-tables.

2) major sports book or casino where non-poker players have $$$$ and may wander over to poker (like a B&M somewhat)

3) pretty skinny bonuses (less "bonus whoring", and i know that's a good site.. problem is that almost all sites seem to have pretty major bonus programs.

any other major factors to keep in mind. i'm thinking party used to be fishy but the multi-tabling sharks have moved in.

what do you guys consider soft sites? i always hear pacific poker. don't know what else. maybe willhill, a major sports betting site (although it is good on bonuses)