There are two kinds of ads or references to specific products and services at my sites. The ones outside the actual post content are automatically generated by folk like Google. I have little control over what they display and do not necessarily endorse the products or services displayed. Google et al do a pretty good job of screening advertisers and displaying ads that relate to the content of the website.
Then there are mentions, links, or ads within a post. All products or services recommended in my posts are things I have used or acquired for evaluation and personally recommend. Of course, if my post blasts a specific product or service, I do NOT recommend them.
I try to make sure to have written an article about a product or service before I include a link or ad for it. Occasionally I might put up the ad before I've gotten around to writing about it. If you can't find my evaluation for a product whose ad you see, you can safely assume I recommend the product and will eventually write about it. If you are really curious about such a product, comment on the post and I'll get back to you.
Frugal is smart; Cheap is stupid!