Attention Seeking Behavior.

One of the biggest problems in American school systems right now is bullying, but few people have taken the time to look at how easy it is to spot a bully in the making. All a bully wants is attention. They act out by being mean to other kids because they aren't getting the attention they need at home, and as you've heard a million times before "any attention is good attention". These kids would rather be in trouble constantly than be ignored, and if they weren't acting out that's exactly what they think would happen, because that's how it works at home. It's not always because the parent isn't capable of taking care of the child (although that's often the issue). Sometimes the parents just work to much, or the child only has one parent and that one parent has to work to raise the child, and possibly others so the kids are forced to grow up faster than they should and take care of themselves. Sometimes it's a result of sexual abuse and the victim feels that they need to get the attention of their abuser because they can't handle not feeling the "love" that they once felt from that person. Sexual abuse is something that can seriously mess with a child's mental development and change them in all sorts of negative ways. There are lots of ways that attention seekers can act out besides just being bullies though, and I'd like to address a few of them.
Another way a young person might try to get the attention that they crave is to post revealing pictures of themselves online. Most of us have seen the guys that pose in front of the bathroom mirror with their shirt off flexing their prepubescent muscles trying to look cool for the girls at their school. And I know you've all seen the girls that constantly post pictures of themselves in their bikinis or their underwear. I'm not saying that there's anything wrong with a girl taking a picture of herself in her bathing suit, at the pool, or the beach to show it off to all of her friends, but there's no reason for them to post a photo of themselves in a bikini, in a full length mirror with their hair done and their make up on. Can you see where there's a difference? In one scenario the girl is taking a memorable photo as a memento of a good time that she had, and in the other she's seeking attention. Often times girls will also starve themselves until they start getting compliments about how skinny they are and how much prettier they are now that they're at an unhealthy weight. If you compliment a person that's ridiculously underweight on how good they look you're giving them the attention they want, you're enabling them, and you're driving them to continue to starve themselves which can lead to serious health issues.
One more way that people seek attention is to constantly flirt. For one reason or another these people feel better about themselves when they're getting compliments from strangers. Sometimes this isn't an issue, but when the person is supposed to be in a committed relationship it can lead to serious problems, especially considering the fact that the person that's flirting sees nothing wrong with it, but if the other member were to do the same thing it would be an issue. This is because the one that's flirting NEEDS attention, and if the other person is flirting as well then they obviously aren't giving the attention seeker the attention that they crave.
One way that children (especially young children) like to get attention is to cry or whine. No good parent wants to think that their child is suffering so they often jump up from whatever they're doing to make the child happy, and stop the crying. If a baby is hungry it cries, if it's thirsty it cries, if it's bored it cries, if it just feels like crying... it'll probably cry. If a kid wants a toy or some candy, they may cry to get their way, and if you give them their way they're going to think that crying or whining will get the job done next time too. By letting them manipulate you you're opening the door for repeated fits. Your best bet is to defuse the situation some other way and DO NOT give them what they want. Tough love works.
The last situation I want to touch on is one where the attention seeker will create drama for no apparent reason. There's a really easy way to spot these people. If the first thing you hear out of their mouth is "I hate drama" they're an attention seeker. If they didn't love drama their life wouldn't be filled with it and it wouldn't be on their mind at all times. If they weren't thinking about it then it wouldn't have been the first thing that they said or typed. It's very difficult to deal with these people because they're guaranteed to kill a mood and it's hard to be their friend (unless you're an attention seeker as well) because they're constantly whining about how so and so is an asshole because __________ and how they're never going to talk to ________ because they did something they shouldn't have done according to the attention seeker. These same people will often hold on to their exes for far to long because they know that as long as they have someone to hate they can always get that attention that they need to fuel their self esteem.
Do no fear. It IS possible to correct attention seeking behavior. All you've got to do to stop it is to not participate in it. Avoid the person when they're seeking fuel and refuse to give it to them. What they really want is to control the situation, and if you don't allow them to manipulate you then they have no power over you and can't feed off of you. Obviously it's going to be hard to ignore them completely because it's a person that you care about, but if you slowly work towards not giving them the attention they need (which is easier said than done in some situations) then eventually you might correct the problem. There will always be a little bit of bickering in a relationship, but constant drama wears a person down and causes them to gradually care for you less and less until they no longer want to be with you at all. So if you're an attention seeker and you love the person that you're with, it may be in your best interest to recognize that you're the issue in the relationship and correct the behavior.
There's LOTS of literature on the web, and in books regarding this topic and to be honest I could probably write 10 more pages about this myself, but I think it's best that I leave you with this brief overview of the issue and leave the real educating to the professionals. I'm just a dude that happens to be very observant. A guy that's watched a lot of relationships and friendships fail as a result of this kind of behavior.