Business Opportunity for VPS providers - Asterisk PBX
As I mentioned in my other discussion I "used to" (they shut down) have service with a VPS provider who offered Asterisk template. There are not that many VPS offers with this out there.
A business opportunity for a VPS provider: create a Trixbox (or other Asterisk distribution) template (most feasibly done under CentOS) and offer to customers. You would need to run it on non-oversubscribed servers, and usually the fee for that would be higher. Maybe offer it with KVM plans (usually at least 512 MB of good RAM access/usage is required for Asterisk). Good peering is a must (latency, latency, latency).
Believe me, there are many people out there who would jump on plan like this, if you promote it properly. There are many people who want to use VOIP and need a remotely hosted solution, which they can set up with couple of clicks. Yes, there are providers who offer Virtual PBX paid solutions, but they charge on per-line/per-call/per-minute basis, etc. There are many people who do not want a plug-n-play solution, but rather a template they can configure themselves, but do not want to go through troubles and complications of installing and tuning Asterisk PBX (e.g. trixbox) from a command line console.