I have been doing a number of trials and demos recently for different products some are 15 days and some one month. Many of the companies send an email from a live person on the 2nd day of the trial asking if I have questions. Some companies follow up with a phone call. Before the trial ends they touch basis again a few days before expiration.
One company whose product I really like sent a live person email on the 2nd day, on the 3rd day sent an email on the training videos, on the 4th day sent info on bi-weekly webinars, on the 5th day sent an email on the frequently asked questions page, 6th day sent an email on comparisons to other competitors which is where I am currently at. The progressive emails with more and more info are very informative. It's a 15 day trial. I am very impressed.
In sales, follow up is so important because people get busy with other things and sometimes just forget. It's important to ask them during the trial what they think.
Edit: The product with a lot of email is an all encompassing ecommerce plattform. In this case I did not feel it was sapm as I actually felt the emails were useful.