If by effective you mean they get people to buy things they otherwise wouldn't buy, and really don't need, I tend to agree. I'm a firm believer in capitalism and free markets, but I feel people shouldn't be coerced into buying things by slick advertising which makes products seem better than they really are. Rather, just have some sort of information exchange where people wishing to buy a product might go to learn more about the product. The information could include specs from the vendor (with some mechanism to ensure such specs are honest), other general information about it, and of course the opinions of actual users. Actually, such things already exist more or less at places like Newegg and Amazon, except as far as I know there is no mechanism to determine is the vendor's specs are true. What shouldn't exist at all is any kind of advertising where a person who isn't seeking to buy the product is bombarded with information about it. It might be OK (and this a gray area in my opinion) to have links to similar products when you look at a product.
What's not OK, and this is my beef with advertising in general, is to have interruptions of your TV program, public displays like billboards or displays, telemarketing calls, door-to-door salespeople, advertising flyers, and any other means where you push your product to people not actively seeking to buy it or similar products. It's OK to have advertisements in trade journals and the like because by definition those exist to show the end user new products. Also, most are not read by the general public. You can do likewise in magazines catering to a specific niche, like cycling or photography. However, magazines with general circulation and newspapers really shouldn't have any form of advertising. I know this is contrary to their business model, but the idea here is to keep the ads to people only likely to buy a particular type of product anyway. And prescription drugs shouldn't be advertised at all to the general public. By definition a doctor decides if you need a prescription drug. Doctors don't need to waste their limited time explaining to patients why the drug with a commercial with blue skies and pretty flowers isn't the right drug for their patient. In fact, doctors should sue the drug companies for all the time they waste doing this on account of all these silly, misleading drug commercials on TV.
I'm totally against non-print, non-online ads, or online ads involving popups, spam, and anything else intrusive or disruptive. An ad should at most be passively available for those wishing to read it. It shouldn't be forced on people or disruptive. For example, telemarketing by far is the most disruptive, stupid idea there ever was for advertising. I continue to be amazed that telemarketers get enough business to make it worthwhile given that they're calling people who don't want to be called to sell them stuff they don't want to buy. The do-not-call list has been a joke. My proposal for dealing with telemarketing is simpler. All phone service providers have access to a universal list of spammers. If a person who is on the do-not-call list receives an unsolicited call, they press a button and that number is added to the list. Once on the list, the phone service provider legally has to make sure any calls from that number don't get through to anybody on the do-not-call list. Any calls where the caller id is spoofed or blocked don't get through either. In a few short weeks with this system the telemarketers would be out of business for good as they couldn't get through to 99% of their potential customers. To prevent personal phone numbers from getting on the list in case you dial the wrong number and someone on the other end thinks you're a telespammer, there could be a separate list of phone numbers known to belong to residences which can't get put on the list. You could still catch telemarketers trying to beat the system by using their home phones if the phone service provider detects an unusual amount of calls made (say more than a few hundred per month).