Offering an insight, then concluding with, "just saying" then undermines whatever insight you proffered. It should be abolished, if possible, as it is self-sabotage. It is a trait of not considering why you were attempting to persuade. It is akin to punctuating your phrases with "um" as commas and then no one will take you seriously.
If you offer a sincere observation and maintain eye contact, there is a chance of planting a seed. Then listening to encourage it to develop.
If you say, "just saying", then immediately it zaps the power you had in communicating friendship.