in the early years demos were not as closely guarded as they are today
the band would routinely give copies of their demos to outside collaborators, producers, friends, radio guys, other musicians, etc

the earliest demos from the pre BJ era were widely passed out in hopes of finding a record deal, there are actually three different sets of different demos from this era, some of these eventually became part of the 1st BJ album

there are no circulating demos from teh 7800 sessions as the band wrote virtually in the studio in a very short period of time and there were no "leftover" tracks per se. When the band retrieved the masters from the origianl studio from the first round of CD remastering, they had been sitting there since 85 untouched, there were some alternate mixes and extra takes but no extra complete songs

There are lots of demos from Slippery as it was a bigger production with lots of extra people involved, multiple studios for recording mastering etc. Same deal with NJ, both had many different sets of demos, and lots of folks handling them who shared with the world.

KTF marked a real change in the way Jon looked at the whole recordings thing. He had a notebook full of lyrics "disappear" and had seen the earliest bootleg tapes of demos hit the private trading circuit. A concerted effort was made to keep things a little more "unreleased" by then. A few demos exist from this period in mostly complete form probably turned free by post mastering facilities.

Richie was very free in allowing folks to have demos from his rehearsals and sessions for stranger.

THe new tracks for crossroads were the first done to much extent beyond real rough 8 tracks at Jon's house and were short and sweet with no time for horseplay

These days was very lean pickins for demos, there are a decent stash of them but they aren't trading, and might never.

destination anywhere was a tight ship

Jon previewed a bunch of demos at a private party for either an upcoming solo album or the next Bon Jovi album, at the time he said he wasn't sure which would be next, it's on the tape but most people refuse to believe he was considering breaking up the band at that point.
these circulate in very poor quality and came from a cheap tape recorder used by a worker at the party.

a few of the tunes eventually made it to soundtracks and the next BJ album Crush

There are demos of a sort for the Undiscovered Soul album. A nearly finished mix was stolen so the Japanese release was rushed to "beat the bootleggers", the version the rest of teh world got was slightly more "finished"

Bounce demos appear only in a solo'ed mix of thte album tracks which came from a mastering house.

Since 87 the band has released thier favorite demos as finished tracks for B-sides

Paragon