It looks like Linkworth and Textlinkads are offering more and more similar and competing services. I must admit, I like the Web 2.0ish interface of textlinkads. Linkworth’s interface is a little old-fashioned, but works with no problems.
I am still making more money with linkworth, although textlinkads are catching up quickly. I started with linkworth first as they generally accept any site. Textlinkads only accept sites with a pre-defined page rank and alexa ranking.
Linkworth possilbly have a larger advertiser base, but I am only guessing at this. What it means for publishers however, are increased money making opportunities.