Bad ideas when marketing yourself

I use Facebook to market myself as well as the website and the blog, haven't quite gotten into twitter yet.
These social mediums are great ways to make contacts and for causal communication to keep your customers and potential customers in the loop with what you're doing and what you can offer them.
There's a dark side to this though, not only can the customers see the positive things you can do, they can also see the negative things you do, those hidden actions that give away your true intent. This morning on Facebook, for example, I got two notices that a couple aspiring local photographers I know have joined this Fan Group.
I was kind of flabbergast at the idea, as one of them works at a retail photographic store here in town and has marked not only myself, but multiple other professional photographers in town as friends, meaning we all see exactly what they now think of the customers that they serve, which isn't very flattering.
Some time ago, a 'new idea' started making the rounds in the world of big business, a concept commonly referred to as 'the waiter rule'. Loosely summarized, the idea is that if you're out to dinner with a customer or vendor, and they treat the waiting staff poorly, then this is probably a person who you may not wish to do business with. The logic is that everyone puts their best foot forward when they want to impress someone, but when they think no one is looking their true nature comes out, and someone who is disrespectful to serving staff will be disrespectful to you when you're not looking.
Back to the groups within Facebook and other social network sites, these particular items are much like a digital date, you get to see what your potential business associate is like when they let their guards down. Certainly, if you have a consultation meeting with the client, they'll be on best behavior, but if you have skeletons in your closet (Halloween reference) on your online presence, well, customers may not be so keen to work with you.
Granted, this particular group is a little less offensive, and anyone who has worked retail, or food service, knows that it can be a very trying experience, but this is no secret to anyone. Revisiting it regularly, and in particular participating in publicly mocking or complaining about it casts a poor light on you as a person, and a glaringly bad light on you if you're trying to market yourself. It demonstrates to the customers that you're only going to be as professional as you need to be, and beyond that you don't feel a need to care.
There are worse groups to join than this one, anyone on Facebook sees them come up from time to time, groups that actively promote hate, distrust, arrogance and social discord, but for the sake of professionalism in this blog I'm not linking to any of those.
The next issue that should be addressed, while I'm here speaking to the point, is netiquette. There are certain rules for posting on the net that are similar to how one communicates in a business environment. Some rules should seem obvious, but they're often ignored, and doing so may cost you credibility in your business venture. In particular, two that are most overlooked are the use of vulgarity and poor spelling.
It's pretty easy to spot the difference between a seasoned Pro online and a young passionate start-up simply by the language chosen. Professionals will keep the language conversational and upbeat, and most importantly, unoffensive. Spelling, which I struggle with, is also important, take the time to try to get it correct, at least that shows an effort to be professional. The worst thing you can do is completely ignore it in hopes that everyone out there will think you're too cool and savvy to care. Keep in mind that often your clients (particularly in Wedding photography) are getting financial help from family members, and if their aunt who has offered to pay for the photographer sees posting where you cite things in text slang an vulgarity, she may be offended or insulted and insist another more professional shooter be contracted.
In summary, online networks are great, they are inexpensive and reach far more potential customers, but they must be used with intelligence and professionalism. Keep in mind that the waiter rule works both ways, as well as the fact that because you and your friends may think it's okay to slap about vulgarity, not everyone feels the same way. These are small details, but as the saying goes - 'the devil's in the details', and ignoring these simple rules could be costing you credibility, respect, your reputation and in the long run, money.