@rusomike90, although I do kinda feel like your post came out of nowhere, here is my response:
The three areas I would be concerned for loss of user experience would be:
- Speed
- Appearance
- Usefulness
SPEED
Since we are all users of BHW here, I did a quick comparison of one of my heavier traffic sites, which is using Google AdSense, and of BHW. I am doing this as a comparison, not as a criticism. I understand BHW is orders of magnitude larger than my site, but BHW is using premium forum software (xenforo) and I am using free forum software (phpBB) on this site, which seems to add some "bog." I used, what may be a biased tool for this, Google PageSpeed Insights to test both sites. On Mobile, my forum is keeping well below BHW's First Contentful Paint, Largest Contentful Paint, Cumulative Layout Shift, and Speed Index. BHW was 30ms lower in Total Blocking Time. In the JavaScript realm, BHW is doing a lot more than my tested forum. Both are seeing an increased load time with Google Tag Manager. I am only using Google here whereas, as I mentioned, BHW has a few additional JavaScript loads which adds more load time. Both sites could minimize code a bit better, which I may play with later. On Desktop, the gap grows and my sites speed performance increases ahead of BHW. Overall I am very happy with how my site is performing.
APPEARANCE
Since a goal of mine is to provide a quality community and resource to the users appearance has been very important throughout this entire project. I have played with AdSense over the years and am familiar with how it can get out of hand, especially if you give Google full access (Auto Ads). I am creating specific Ads for each forum and only placing them where they will not negate the user experience. This is not ideal for advertisers, but advertisers are not my target audience. Too many sites lose track of who their target audience is. They tend to believe if they cater to the advertisers they will make more money, which may be true in the short-term. But for a long-term, more lucrative experience, they should cater to the users, which is the strategy I have taken with this project.
USEFULNESS
Wherever possible I try to keep the advertisements in line using the Blocking Controls and other checks. Also, if you have been reading this thread since the beginning you may remember I weened my users into advertisements by placing cross-forum advertisements initially then working them into broader advertisements. I am still placing ads for my other sites, which would reduce the load time as those are just a local image pull, and which would be of possible usefulness to the users as I only do this where the interests may intersect. Based on the advertisement clicks I could see that the users are finding the advertisements of use.
Google AdSense does have an approval process which requires some type of minimums in content and perhaps traffic.
As I mentioned, my focus has never left the user. I see it as follows ... A business usually exists to make money. A business is often comprised of investors, employees, and customers. The person running the business, let's say the CEO, is responsible to the investors, and in some instances to the board, to make money. Foolish CEO's place their priorities as 1) investors/board, 2) employees, 3) customers. Higher quality CEO's recognize that as being backwards and place their priorities as 1) customers, 2) employees, 3) investors/board. As you implied, the reasons for this is, if you focus on your investors and employees you neglect your customers. If you focus on your customers then the others will self-align. This concept is true within all types of organizational structures, businesses, communities, families, sports teams, even nations.
When you say, "monetization will come later", I think you may not have been following this journey since the beginning. This thread is almost one year old. At what point is it acceptable to start monetizing? What is a "substantial user base?" The answers are unique to every instance. In this project, I have been very active in each community and am intently tending to them. I am responsive to each community and helping them grow into their own. "Later" is always there. Knowing when to act "now" is what separates success from failure.
In each forum I open up with the community about advertisements. After reading your post, I double checked, and I have not received any negative feedback regarding advertisement usage. The comments I have received is that I am incorporating advertisements in-theme and tastefully. So far, my forum communities have little heart icons over them and they are content. I will continue to keep an eye on them and adjust course to keep them that way.