I think this should be rephrased more accurately as "Should You Start A Business?"
Or perhaps "Should You Start A Non-monetizable, Easily-clonable Business In An Already Crowded Market?"
Or perhaps "Should You Start A Non-monetizable, Easily-clonable Business In An Already Crowded Market?"
The scale of Facebook resources (or Google's for example) makes it easy to clone pretty much any product that fundamentally enables two or more users to interact. At a certain scale of resources, most software products are easy to clone because rarely are they based on some fundamentally new/patentable/distinguished technology. What's hard to clone is the interaction, and it's for that reason that this probably wont make much difference to Snapchat. I've only used Snapchat a couple of times in the past and the type of interaction it enables doesn't relate to the way I think of Facebook at all (and I suspect this will be true for most Snapchat users). Ultimately, almost any app, at infancy, is easy to clone - Facebook could have cloned pinterest/twitter/path/quora etc (and at times it tried), but that's not what killed them/would kill them. If they do die, it will more likely be from not tending to their community & executing on their vision. Frankly having Facebook clone your product is probably worth its weight in press alone.