Skyworks are the best in the business when it comes to putting adverts in-front of you before you can get to your pool game.
They provide many of the games which you may already play. You can usually notice them by the slick logos which are merged into the game itself.
I'm sure you've played the Oreos Pool Game at some stage or you may have come across the more recent ESPN Arcade which has many casual games including of course pool games.
The question here is, should you be annoyed by all the advertising showing up inside the game you're trying to enjoy playing or is it all part of playing pool online?
I would say it's a necessary part of playing games for free online. It's companies like this who are keeping high quality games free to play for you and me. Who cares if there's an Oreo or ESPN logo on the table? Better that than having to pay to play the game.
There is a growing trend on the internet in general for games to become free and have slick advertising through them. This should be OK as long as the advertising does not interfere with the game play itself. I'm sure you've done the same as I have and accidentally clicked on an advert when it pops up, right before you were going to click on another button. This is known as an "interstitial" in the business and is a very intrusive version of advertising on games.
If a place you're playing at does this and it gets in the way of your pool game, complain! There are enough ways for sites to advertise around and inside games without forcing you to accidentally click on their advert.
So, lets work on keeping the pool game sites clean and let them know when they go too far then we'll all enjoy our games that much more and they will be able to keep us playing.