Should I keep writing?

I see potential also. No introduction is not good. You should always have an introduction in all articles. I also noticed a lot of grammar issues. No commas where there should be, etc. You might want to look into this also. Overall though, a good start and I have read a lot worse.

The main purpose to an introduction in an article is to introduce your reader to the subject matter you are writing about, and to also state the intent of the article. It does not have to be long. A few lines should be enough, depending on how long the article is.

It kinda comes from 2 things

1) Seeing how other marketers are doing it, and

2) Practicing

That sounds lame, but it's true. There are lots of different ways to write online (product reviews, press releases, articles for syndication, articles for SEO), and getting good at them just takes some knowledge and practice.

Read this post on Copyblogger:

A Fool-Proof Formula for Easily Creating Compelling Content | Copyblogger

This will give you a good outline for an entire article. Pay attention to the section that discusses the hook. This is what you want your introduction to do, hook the reader into reading the full article.

Ryan, I just read through the SEO article. Based on that, I think you definitely have a genuine knack for writing (something far too many article writers lack).

As for feedback - one thing I noticed is your over use (overuse? sorry - it's late and my brain is mush!) of commas. As a result, some of your sentences are too long and could easily be turned into two or three sentences. The very first sentence of the SEO article is a good example of what I'm talking about.

The other thing I noticed is that you often used capitalization when it wasn't appropriate or needed - e.g "search engines, "search engine optimization" and "campaigns" (after PPC) are some examples of words that shouldn't be capitalized as a general rule. I understand you were introducing the reader to SEO and why it's important. A better way to do that - and only when you first use the phrase in the article - would be to put it in bold letters or italics (or maybe quotation marks) instead. (Might be okay to keep the caps in the last paragraph when you're highlighting the service offered...)

I'd say you're off to a very good start! Get off Fiverr and start marketing your writing services. And don't sell yourself short when it comes to pricing!