The services offered free is not something new as it has been said here several times. I have tried several times on using the via btc accelerator but its just fully booked for the hour due to limited transaction to process the other is something I would want to patronise after there is enough reviews on how potent and effective it is.
It worked for me several times tho . It's always fully booked because they have an hourly limit of 100 TX's and If I were them I would have done the same cause if not I bet lots of people will abuse it and most probably the TX's entered on a certain day will probably receive confirmations the next day or the day after that . If you want you can use their paid service
Seems like not all people knows the trick on what time you have to submit a TX on viabtc, You shoould submit it at XX:00:00 (forum time) . Worked for me and to others .