I think J2EE is going to more saleable. An easer sell to tech people and an easier sell to VC (venture capital) people. These people want the latest buzz.
I have to admit this goes against my limited experience of VCs.
The VCs I've been involved with do not give a flying fig about the technology involved. In fact, if anything, they have a bias against the "latest buzz". New stuff is untested and might not work. Other people tend to jump on bandwagons, so you instantly have more competition for the business if it's all built around a particular "new" technology.
The only area that VCs care about technology is "How does it support the business plan?". Show that technology Foo can meet the business goals, and mitigate risks, better than technology Bar and they don't care what Foo actually is.
How can I make perl/mod_perl more saleable?
Generally - push out the usual success stories. Specifically - show how it will meet your specific business needs better (i.e. cheaper, faster, more flexibly, etc.) than the alternatives.
How can I promote perl/mod_perl scalability vs. J2EE?
Generally - show them success stories like the BBC where they're pushing 500 requests per second. Specifically get the expected numbers for your business domain, design an architecture that can scale, do a quick spike solution to demonstrate it works
How to overcome the term scalability for people who really have nothing to worry about but think they do?
Numbers. Dig out the business plans. Look at how many numbers you can expect. Design a nice decoupled system than can easily scale by just adding boxes. Say "Look - we can start here and if we're stupidly successful we can scale by adding N boxes to the datacentre at Foo for $XXX.
I don't see anything j2ee can do that I can't do with perl/mod_perl. Why is it percieved as "better"?
Off the top of my head:
Is this just a marketing thing or is there something I am missing?
I don't think it's just marketing (at least in the narrow sense of Sun spending money to promote Java) although that's certainly a component.