Interesting, we were under the impression that the groups actually speed up the game, because anyone can put in a smaller amount at any time, as if it were round 1, but we're open to suggestion on it!
Suryc - when switching to a group bomb, the timers are extended. This gives buyers the chance to buy solo, then the rest to group in.
-You refund all incomplete shares
-Bombs that fail to be bought solo go to group automatically - Makes them live 24h more
-There are much less bombs being bought from groups than bombs being bought solo
Read those 3 again, and understand you'd make more money and would have a smoother game if you'd either:
-claimed a fee to upgrade to group bomb (10%, all in your pocket)
-downgraded the solo timer to 8 hours, and group one to 16 hours.