Spike has occasional hits like Kenka Bancho:
http://ds.ign.com/articles/107/1074871p1.htmland their budget for games is practically nothing.
I mean did you see the "average Japanese game budgets" article that came out a month or two ago? Your average DS/PSP game costs like 100-500k to make. If it sells 100k copies like Kenka Bancho 4 did @ $40 a pop to the publisher (assuming the price is about 6000yen), you're looking at 4 million profit, with 3-3.5 million net. More than enough for a small company to coast and develop another bunch of <500k cost games.
Japan has a
very cheap business model for the smaller devs. They know how to make games for cheap, re-use and build on older games to make sequels for cheap, advertise for cheap, and then when they sell 30-50k they do fine and the occasional 100k hit floats them for a couple of years.
Spike's cash cow is Dragon Ball. I'm guessing all of the western games they publish in Japan don't get a full localization. Probably just a text translation, like Yakuza 2 and 3 in the US. I guess that has been profitable for them? 
Although I wish they would funnel all of their money into an HD Fire Pro Wrestling with GGPO netcode and a new King of Colosseum so they can go out in a blaze of glory.
Oh wow, I didn't even realize they had DB. Yeah that's more than enough to keep them fine.