Your experiences outsourcing product fulfillment?

I am looking for feedback from people who outsource their product fulfillment on the pros and cons of their service providers! I think the information will be helpful to the community. What should other entrepreneurs be looking out for when hiring an ecommerce or order fulfillment outsourcing partner.

Disclaimer: I have have a fulfillment outsourcing company, and I am continually looking for ways to to be the best in the world at what we do.

We evaluated quite a number of different fulfillment providers and came to the conclusion that Amazon Fulfilment was the last expensive (on the surface), had the most trusted name, and appeared to have the best info systems integration (they're Amazon, after all).

We used a company called iFulfill by Paul Purdue before the owner ran it to the ground and shut the business down with zero notice to his customers. Thankfully we saw it coming, but it was a completely nightmare!

For the last few years, we've been thrilled with a company called William B. Meyer - they are based out of Connecticut, which makes for quick shipping to Western Europe.