Many people do not understand the difference between informing and advertising. Even some regulators are trying to mix things up because then they can play as arbiters guided with rules that are not clear.
Giving information is “emission of related data about requested subject”. That means that if you want to change your cable provider and go or call one of companies that should be considered as informing and not advertising. But, if you get information about some product or service without your initiative, that is advertisement.
In the Internet, having a website is considered generally as informing because people have to enter correct address or to search for your firm. But what happens if you search for a word “water” to find information about chemical properties or pollution and you get water prices and pages that offers you to buy their bottled product? Now you can see that it can be legally complicated.
To solve that issue guide yourself with a simple rule that if your website is indexed by third-party search provider without payment for “special position in the index”, then you do not advertise, but inform.
It is good to be available for information about your products or just about things that you do. The best advertisement would be one that is seen when the customer needs it, but that is not possible. Because of that avoid spamming people with your offers and instead attract them to follow you. That creates much better satisfied customers that are interested and well informed about you.
You should never forget that satisfied customer is the best advertisement you could get!