not to mention, banner ads are the #1 security risk as a way hackers can crash sites and infect your pc.
NEVER, ever buy anything online which you access via a banner ad or ad-server. hack-ads can setup and look legit, so you purchase your item and next thing you know your credit/debit card is cleaned out and wire-transfered thru so many accounts by a guy in Singapore they will never track it down.
sortof like if someone calls you at home and asks for your credit card to buy a magazine or make a donation...would you? no, of course not. well, clicking a banner ad and buying something is pretty much the same level of boneheaded move.
Knowing that, defeats the purpose of having ads on the site, right? well, no. there are plenty of compulsive clickers out there I suppose, so the dry hooks remains in the water waiting for the occational fish going after something shiney. - and if you have enough hooks in the water....
so, yes I agree - banner ads cheapen a site. It's an unimaginative way to produce income to a website. In order to increase a website's value, you don't increase the banner-ad real esate. That will have the opposite effect in the long-term.
Less people visiting = less worth of the ad space.
The way to increase revenue is to increase the quality of information contained on the site - in this case, the subject of martial arts. Thereby increasing visit hits and increasing the quality of sponsorship, decreasing the need for being supported by cheap banner marquis.
so what a MA website should be doing is working on the quality and depth of articles they put out on the front page.