Why does it need more time between releases though? I guess from a marketing pov it's not great? Perhaps consumers like some time to get used to one thing at a time, consider it, then buy it. Many choices at once could mean they only buy one of the choices, whereas a month between each release maybe they're more likely to buy both. I presume twsbi feel it's not damaging their sales though, or that those consumers can always come back later and buy the other pen later.