I own two cars. A 2009 4-door sedan and a 2008 SUV. 

The sedan is quiet on the road and handles like a sports car. The SUV, with its high profile and all wheel drive, is perfect for maneuvering after a snowfall. Plus it holds the big stuff that won't fit into the sedan. 

I wouldn't want to choose between them. This got me thinking, can there be a parallel argument for email service providers (ESPs)? 

If I send a simple bi-weekly templated newsletter to the same audience, a basic low-cost ESP may fit the bill just fine. 

However, if I need a high-touch provider with strategy consulting, analytics integration, and transactional messaging capabilities, I will need a more robust solution.  It will cost more, but if the ROI (return on investment) makes sense - I'm good with that. 

So next time an ESP calls, don't say, "I already got one of those." Ask yourself if you need another one.