[keiretsu]

Now, i am sure some of you have encountered a good-for-nothing co-founder who seems like a good fit early on but turns out to be a disappointment as time dictates. Assuming you've decided enough is enough and you decided to look for a new co-founder, what should be your course of action. Note that your existing co-founder has some equity in your startup.

Should you start a new company with the new co-founder replicating the old startup (which should take about a month at most) or stick with the old company?

P.S. I'm assuming a web startup here. So replication here means doing a similar site.