Things that made me switch:

1) Dont have to carry crates
2) Dont need to buy doubles of vinyl any more to beat juggle.

I don't know if it was any one thing that that made me adopt SSL, but I will try to narrow it down...
First is the amount of music that instantly became available for every gig. Second is the ability to use that media from a single location, i.e. not having to burn dozens or even hundreds of CD's in duplicate or carry a 2nd mirror laptop for the 2nd channel. Third and fourth are pretty much a tie: program stability and vinyl emulation. Next is the support network. If it had not been for this forum, SSL would likely still be on my list of gear to buy eventually instead of making me money now. :)

ps. previewing this post prior to posting myself, I see that mex's 1 & 2 are pretty much identical to mine. :)

Same as Mex

I used to work for Plus 8 records/Intellinet distibution. My bosses, Richie Hawtin & John Acquaviva, became involved with a new product by N2IT... this was the first version of FinalScratch. I saw all the issues they had with it and decided to hold off until they worked the bugs out - that never happened. Then I heard that the makers of Pitch & Time (Serato) were teaming up with a highly regarded audio company (Rane). This piqued my interest and I followed SSL for months leading up to it's release. I was confident in both companies products (having used both) and took the plunge the first day. I wansn't disappointed. Scratch Live was the first product of this kind to actually be stable enough to use with full confidence. I still play mostly real vinyl, but enjoy the digital aspect as well.

for me:

1:no vinyl to carry
2:being able to play and scratch my own remixes and scratches
3:having my whole collection in the laptop so not needing to worry about forgetting that 1 tune or style of music
4:no more buying 2 copies of one record
5:being able to mix cd only release on vinyl

no more wear and tear on my fav records....
my rare vinyl isn't all effed up....
the ability to set a playlist and leave (1.4) (bathroom breaks/attacking the food table)....
awesome tech support....
the mic record feature is pretty nifty....

dont have to rely on record stores for hot tracks, just get new sh*t e-mailed to my from labels. REAL EASY!!!

Besides the obvious "not carry those heavy ass crates", my selling point is i love having 4500+ songs on demand at the click of a button