5. Resources
If the provider does not have sufficient technical resources for your on-going needs, your development may be put at risk.
Check on the resources that will be available when you are interested in getting technical assistance. At least half of the available resources should be very experienced in using the product (typically four or more years). A good balance of less experienced but capable resources indicates a constant influx of fresh talent and internal training, which is equally important.
If training is a requirement, ask if the training will be provided by the provider itself, or by a third party. Some providers are all to happy to hire in trainers and merely charge extra on top, which does not give you longevity or value for money.