What is your opinion about the SaaS product marketing?

It really depends on your SaaS product and who its target users are. For example, a SaaS app for small business owners would have a very different product marketing strategy than a SaaS app for developers. Product marketing should largely aim to be "part of a conversation" between you and your target users, and each time you message or announce something, it should be a value add to your users. For instance, an announcement about a new feature you built should focus on how that feature makes your users' lives easier and position your SaaS favorably against the current market of offerings.