Alternatives to analog lines?

I recently received a mail asking me about ISDN PRI.  It's an effective way to get lots of lines into your business.  But in Response Point we're targeting smaller businesses that typically only have 3 or 4 lines, for whom analog lines are the typical solution.  This doesn't mean support other types of lines isn't on our roadmap, just that our initial focus is on the analog line service that most of our customers have.