Drawbacks of SEO
I've noticed a number of people searching for the terms "drawbacks of seo" or "drawbacks of sem" which I find interesting, because there are really only two drawbacks to either one, and those drawbacks are common to anything you do in business and life--time and money.
But let's dig a little deeper and see if we can be of further assistance. If you're a company thinking you might need SEO services, then this is what you need to be aware of:
1. SEO is an ongoing process. Your site will never be 100% "optimized," it will only get more and more optimized as you put more work into it. But if you have someone spending 20 hours per week doing SEO for your website today, chances are you'll still need 20 hours of SEO per week a year from now. The good news is that a year from now your rankings will be better and you will hopefully be reaping the rewards of having invested in SEO.
2. SEO is not free. If you do it yourself, you're going to invest your time. You'll probably want to invest some money in various SEO tools as well. If you hire somebody to do SEO for you, then obviously you're going to be paying them. There is no free SEO service nor any affordable SEO service that gives you everything you need. Full service, effective SEO is going to cost you a minimum of several hundred dollars per month, if not thousands.
3. SEO is both easy and difficult. My firm often tells our clients that they can learn how to do SEO on their own. While this is true, it's not feasible for most of our clients because it is less expensive for them to pay us than it is for them to invest their own time in learning SEO. However, in some cases I believe clients should learn as much SEO as they can because it will pay off for their business, even if they continue to use our services. It certainly never hurts to know more about SEO if you're willing to put in the time. If you already know some HTML then you'll have a much easier time learning SEO. If you find the task of composing an email to be quite difficult then SEO is probably not something worth dabbling in.
SEO vs. SEM
Organic or natural search results get more clicks than pay per click ads, on average. Generally you're looking at 30-40% of the clicks going to PPC ads, and 60-70% going to organic search engine results. So there is certainly not a drawback to SEO in that sense. However, that ratio may be different for the specific keywords you want to rank for.
Another benefit of SEO over SEM is that there is not a direct cost for clicks. With PPC, you'll pay twice as much for 100 clicks as you do for 50. With SEO you'll pay the same amount for 100,000 clicks as you will for 50. However, this is also one of the drawbacks of SEO in that you'll pay the same amount for 0 clicks as you will for 50. But if that's what's happening then you should probably find a new SEO company to work with.
One more benefit of SEO vs. SEM is that you get residual value from SEO. An SEO campaign is like a freight train. It takes a lot of effort and some time to get it moving, and it still takes a bit of energy to keep it moving, but if you stop pushing it won't come to a stop immediately, and in fact with SEO there will always be some residual value. With SEM as soon as you stop paying the results immediately stop.
I would recommend to almost all clients that they do both SEO and SEM. If they both provide positive results, why not? It doesn't have to be a choice between one or the other. You can run SEO and SEM campaigns simultaneously, and in fact there are some benefits and synergies to running both types of campaigns at the same time. So don't focus on the drawbacks, focus on the benefits.

