Hi,
I am a content writer and have been writing articles for more than 7 years now. I invite you to read the reviews left by my previous clients on the Freelancer page, which are only a testimony to the fact that I research well before writing, and my writing is natural, yet SEO-optimized.
I have written on a wide variety of topics, and as per your project requirements, have in-depth knowledge in the field. All content is manually written, and I check them for plagiarism myself before sending them over. Moreover, I am also very familiar with on-page and off-page SEO techniques, and can ensure that the articles work to increase traffic flow to your website.
I'm assuming this would be an ongoing project, and therefore bid for $2.5/500 words. I can comfortably complete 1500 words on daily basis. Additionally, I have articles running live on Ezine and Hubpages, as well as a few other reputed article directories, links of which I can provide on request.
If you have any more questions, do let me know, and I'll be glad to answer them.
Thanks.