A "tweep" is a Twitter user who is a rookie or a novice by virtue of their low number of tweets. It is also someone on the bottom of the Twitter hierarchy. The opposite of "tweep" is "twitterian."
"Twitterian" is purely a merit-based term that describes an individual with a high number of tweets and is positively charged.
The term "tweep" is occasionally a negatively charged term, as it implies low merit as determined by number of tweets. There is widespread disagreement on whether or not the amount of time than an individual has had a Twitter account should be taken into consideration when determining if an individual is a "tweep."
There are those who believe that they should not be considered "tweeps" despite their low number of tweets because they have had a Twitter account for a long time. There are those who believe that the date of an individual's first tweet has no bearing on that individual's status as a "tweep."
An individual with both a long standing Twitter account and a high number of tweets is occasionally referred to as an "elitist."
You are a tweep not a twitterian.
I have had my Twitter for exactly one month. Started as a #tweep, became a #Twitterian, reached the #500tweetsclub, and became a #tweetingmachine.
I am not an elitist. I am not a #tweep. I am the voice of reason. We can all coexist peacefully. #IAmATwitterian