I went through a complete needs assessment with a client recently. Did my usual review of appropriate vendors and made recommendations. Then we got tripped up by one... small... detail...
The vendor that suited my client's needs optimally in every possible area couldn't support long-term archival of event recordings. They couldn't (or wouldn't) supply the recording file for hosting on another server. You have to keep it on their server for viewing directly from their site. Okay, so how much is it to keep it active per month or per year? Nope... you have to keep a full use contract going. As soon as your creation of new webinars stops, you lose access to all your old recordings. Nice business strategy. Blackmail your prospective customers into remaining active, paying account holders (at significant rates) or else lose their own content. My client took the next vendor recommendation on the list. Could the vendor be getting more business simply by changing its sales model to allow an alternative revenue stream and taking money for allowing access to archived recordings? I think so.
When selecting a vendor, watch out for those details and make sure to think through everything you plan to do before (registration, billing, promotion), during (presentation tools, polls, Q&A), and after (recordings, post-event emails, reporting). I still haven't seen the PERFECT webinar software that handles everything exactly the way I want. So you're going to need to prioritize your needs and match to them.