As a software as a service, it is very scalable. However, we aren't pushing the limits. We're a little company. Only marketing is using the product.

We do not plan to increase usage.

It is pretty scalable. I would rate the scalability a nine out of ten. 

I rate MailChimp's scalability a nine out of ten. 

Once your email list starts to grow and you send more emails each month, you'll have to move up to the paid-for tariffs. In scalability terms, there are cheaper products out there, so I'd recommend this for smaller businesses and projects to keep to the free account. When you're ready, shop around to make sure the paid-for tariffs work for you.

Dynamic behavioral targeting is not possible. As I work with clients who wish to scale their operations, this will result in an inevitable migration to a more sophisticated tool.

The basic MailChimp services scale well. The Salesforce connector, however, scales very, very poorly.

No issues encountered.

No. Along with most of our clients we are a small business so the lists we manage are all under 10K and pretty easy to manage.

We have not tried any of the other features such as the 360 integration that relates to eCommerce stuff which is where I would imagine scalability may be an issue.

No, even when we've had clients sending over a million emails a month we never saw a difference in delivery rates, bounce rates, etc. It scales without an issue.

I was pleased to not have any issues. In fact, after a month, I found that a customized tab can be added to my Facebook author page to help me get more exposure. It has helped me gain traction and was very easy to link.

MailChimp allows us to create as many campaigns and templates as we want, so there are no issues so far with scalability. Some advanced features, like automation are offered as a paid service.

A definite advantage to MailChimp is the ability to easily scale. They will automatically check how many subscribers you have and move you up to the next level of service, if necessary.

There were no scalability issues, in regards to list size. It was only when it came to wanting more sophisticated automation capabilities that there was some scalability issues.

No issues encountered.

Yes - the list management can, at times, be somewhat confusing when using different form factors.

There were no scalability issues.

No issues. We have had lists from 2,000 subscribers to 50,000.

No issues encountered.

No issues encountered.

No issues encountered.

No issues encountered.

No issues encountered.

No issues encountered.

I do not know if we will increase usage. This will depend on the growth of our work.