In this article, I will mostly talk about the evolution in your product, in general, mostly related to the interaction with your users. Note here the term "users" could represent clients, non-registered users, members, developers, etc. It should be seen as a general clarification of who use your product.
Perception of "Enhancement"
An interesting observation is the perception of the term "Enhancement" a lot of people has. By definition, the term is defined as "to improve the quality". Despite the fact that the context provides a positive minding, a lot of people perceive that term from a negative POV such as "if there is an enhancement then something was bad, erroneous, wrong, etc. before". As you can see, some interesting discussions might evolve from such a minding.
Whenever you release new features for your product, those may fit within additions or enhancements to actual features offered by your product. In most cases, your enhancements are being put on top of what was already excellent before. It is part of the evolution of a product to come up with new features and such. However, the use of the term "enhancement" for some individuals is used from a negative POV.
Unless you are releasing a patch, a fix or similar, I would go in favour of a terminology which would avoid any confusion. Such a terminology could be "We have released some new features...". Basically, if it is an addition then it is a new feature. So, it fits well within the context.
Filter your users
As good as your product can get, you will never reach a satisfaction level which would target to 100% of your users. As your product evolves, this is less than likely to happen. There are several factors which affect those statistics. One of them is certainly related to the fact that the more users you have, the more difficult it is to keep your users satisfaction average high. This is the way the batting average for a baseball player is calculated for each presence at bat. For a baseball player, it is easy to get a high batting average in April. If you get a good start, your batting average will be high. But, add a few hundreds presences at bat a few months later, and even if you hit 8 base hits in 8 presences at bat, you will not reach an average as high as if you would be in April. That is the same as for your number of users. The more your have, the most difficult it is to keep everyone satisfied.
Another factor relates to your company and product expansions. That seems to have been a situation many companies have faced in the last decades. For some kind of reasons, it seems to be more easy and tempted for users to complain about almost anything as a company's entity is growing. It is probably something that fits within the "Unsolved mysteries". Rarely you will see users complaining about specific issues for small companies that offer limited services. One factor could be that most of those users do understand that the corporate infrastructure small companies have to deal with does not allow them to evolve and to provide the best quality of services as fast as it should be. As companies are growing, that same set of users could change their minding and could find any little opportunities to express their POV.
So, as your product evolves, you might as well be ready with a good based support and quality control infrastructure to be ready for those situations. Doing such, you will also find that those typical users are usually represented by a minority and you will rapidly find that your infrastructure relies on the majority of your users which believe in your product and are happy to use it. Filtering your users complains and suggestions, by considering that factor, is one little step ahead in order to make the best of your product.
New releases attract suggestions
One of the most interesting moments during the evolution of a product is when new releases see the light of day. It is a great occasion to release some announcements to let your users know about it. Those announcements can be delivered by the use of various mediums. They can be delivered either as news on your Web site, in a dedicated section which archive all the releases, by email for those who requested them or from any other related mediums which will provide the information to the users.
But, be ready! Whenever you release something new, this also creates an occasion for your users to request more. Whenever you attract your users to something new, they are also into making new suggestions in order to help you evolve your product. This is similar when you want to purchase a car for example. At first, you know what you want. Lets assume you want a manual transmission car with CD player, an air conditioner and one which will suit the needs for your family. Then, it is time to go for a road test. While you do it, you keep talking with the salesman which is seated next to you. Then, while talking about the nice features of that car, you realize that it would be cool to have tinted windows. In this case, it is an example of a suggestion which would fit as per your new release. But, while talking to the salesman, this could have leaded to go for another car and then you are on for another road test. The same happens a lot with the release of a new feature. You suddenly end up with a dozen of new suggestions about something that is not even related to the recent one you just released.
Silent users versus vocal users
One common situation I have faced releases after releases is about the fact that satisfied users are those who talk less. In most situations, you will face it as well. From a user's perspective, when everything goes well or when they are extremely happy about a new feature which was awaited for a while or about one which is really making them more productive when using your product, it is less than likely that you will hear that much from them.
That is just the way it is. And, that is quite ok as there is nothing wrong here. The majority of them represents the silent portion of your users. Of course, it would be nice to receive some of more feedback from satisfied users when such situation is encountered. The same goes for an appliance apparel, for example. You have purchased that new TV and it has worked well for 5 years. Then, suddenly something got broken. This is where you will initiate some procedures in order to get it repaired. So, this is when the product owner will hear from you. The same is true for your product. The vocal portion of your users is mostly represented in those situations.
Being productive with complains and suggestions
One aspect of the evolution of your product relies on the complains and suggestions provided by your users. In some cases, a complain will include a positive value and you would want to take the most out of it. Of course, it is always more interesting to receive a suggestion as you don't have to turn a negative situation into a positive one.
From a product owner, it is always more interesting to read something from users, about a complain, which is formulated into a suggestion. For example, some of your users might be frustrated about something that might not even be related to your product. But, as they don't know, you are the first one targeted. In such situations, the complain received may seem extremely cold. Basically, you just don't know how to react and answer that one. So, such a complain could come in various ways and one of them might be: "Hey! What did you do? The change you did makes my toolbar to disappear. This is really non sense!". Of course, we would have preferred to received something like: "I don't know if your latest change affected or not my toolbar. It is not showing anymore. Do you know if this is related? If not, do you have an idea of what I may check on my PC for that?".
So, in the latter situation, the feedback provided by the user is more productive as you don't have to worry about negotiating with someone in regards to their temper. When providing support to them, such as during a phone call, the tone of the voice is already calm and that helps in solving the situation faster.
No matter what you do in trying to avoid those situations, they will arise occasionally. It is just the way thing works. However, you may work on educating them on that process by providing a good support documentation for your product. That could include specific sections in it to deal with those issues. The text may educate users on the fact that it is much more productive to work together in order to solve an issue than to receive a really bad feedback which doesn't help at all to get a good start.
A good support system
When negotiating a support request, in some cases, this will result in the addition of a new feature for your upcoming versions. The evolution of a product contains a certain percentage of new features coming in from such situations. When you face them, you might as well provide a good support engine to populate them.
An interesting support engine for your product is one that will make your users involved. And, not only the importance is to have them involved, but also to have them participate on an ongoing basis from the same support request. That means provide them feedback on those requests so they know the current status of each of them. When applicable, you might as well make it public and have other users involved in the discussion that might be issued from those support requests.
Avoid making use of email for such a support engine. There is nothing more frustrated than to have to negotiate with an email address to provide support. First of all, there is no protocol in regards to your support engine and the content of the email. So, it is difficult to extract valuable content from it. The users also will not have to remember a specific email to send support requests if you provide them an engine which is easy to access.
Provide some fields which will allow the user to enter some data into the appropriate sections of your support request form. But, don't define too much fields. It has been proven that forms that are too big are likely to have a bunch of empty fields or a bunch of fields which will contain erroneous information in case you force the user to enter some data in each of those fields. Just negotiate with the minimum required fields necessary for you to offer a good tracking of your product support. Don't forget to include a status field. This is one of the most important fields that serve as an interaction with your users.
I hope this article has provided some information which could be useful for any product of yours. As I said earlier, this was just intended to cover some aspects of the interaction with your users. Of course, there are many other factors that are part of the evolution of a product which are as important as any other related ones.