I had an issue while integrating JavaScript with forms. When you embed JavaScript, you can either embed it in a landing page or some other self-contained management system like WordPress. Currently, it provides you access to CSS, where you can customize your form design, but there is no option for JavaScript modification for a particular form. This area needs to be improved where you can integrate JavaScript, and it has the JavaScript functions for that particular form.

There are a lot of other areas of improvement. In the design area, they can give us more testing options instead of relying on email testing alone. It would be great if they can provide responsive testing where email clients can be tested within Marketo. It would be also helpful if they can implement some in-built options for users or forms for blocking a generic email ID such as Yahoo or Gmail. Similarly, it would be helpful to have JavaScript features and forms as well as the option to add Google analytics and a header and footer for the landing pages.

Revenue management, attribution, and ABM can all be improved.

Its APIs need to be more flexible because there are some things that are not available in the API. They should work in that area and improve it.

Adobe, the parent company, needs to improve on getting more information published to allow users to educate themselves on how to use the solution. You cannot find much information about Marketo on the Adobe website. I had to Google around and go to websites to get familiar with the system. 

For an upcoming release, the UI could improve.

It could be more scalable.