They changed the rules a few days ago allowing anyone to send in any amount with no limits (9999 but who has that amount to send for upvotes). This has caused their Voting Power to decline rapidly. Recently it was in the 80% range and was paying out well. Currently it is down near their lowest allowable power at 59% because so many people are calling on boosts right now.
Keep an eye on minnowbooster.net to watch what their Voting Power is doing and maybe wait for the service to get some rest and some VP back before sending for a boost.