The single most important consideration in choosing a logo design should be its intended purpose. To aid your decision process, let's first define terminology, and then look at some examples.
From Merriam-Webster's Collegiate® Dictionary:
logo | logotype 1 : a single piece of type or a single plate faced with a term (as the name of a newspaper or a trademark)
2 : an identifying symbol (as for advertising)
masthead 1 : the top of a mast
2 a : the printed matter in a newspaper or periodical that gives the title and pertinent details of ownership, advertising rates, and subscription rates.
b : the name of a publication (as a newspaper) displayed on the top of the first page
Not very helpful, is it?
These terms were defined in 1816 and 1701, respectively. As they apply to current-day usage, and particularly as related to Web design, we interpret them as follows:
logo - an image representative of a name, trademark, or servicemark... of fixed size
masthead - an image representative of a name, trademark, or servicemark, used as an integral page design element... of fixed size or not
In other words...
A logo can stand on its own as a design element. Although it can be scaled in size to fit the media, its size as it appears on a webpage is static in relation to other page elements.
A Web "masthead" typically integrates into the design theme of the page, and would not usually lend itself to stand-alone usage as a logo.
Confused yet?
Some examples should help. Look at the top of this page. It has a logo overlaid on a Web masthead. The logo is The Whole Internet name within the green gradient circle-and-bar design.
The masthead consists of the two green stripes, the gray bar, and the text within. Notice how the top green bar has a right-arc, while the lower part of the gray bar has a left-arc that blends into the gray column. Now, resize your browser window.
The logo stays the same size, but the masthead adjusts to fill the space. Please review the discussion and examples on our Putting It All Together page for further information. Click the buttons below for additional examples.
All logo packages include unlimited colors, shadow, etc., within technical limitations (e.g., you can't define transparency in the JPEG format).
Note that although we do not charge extra for additional colors, if you are intending your logo for printed material, your print shop likely will charge you extra!
Multiple concept proofs (Standard: 2)
Unlimited development revisions to chosen concept. We'll work with you until you are delighted with the result (though many are approved on first draft).
Up to 3 Web-ready files (your choice: .gif, .jpg, .png), or 1 file with animation.
Deluxe logo packages offer all the features of the Standard package, plus the following enhancements. This is the preferred choice for printed media (e.g., business cards, marketing material) and embroidery.
Three concept proofs
Up to 3 Web-ready files (your choice: .gif, .jpg, .png), including 1 file with animation.
name within the green gradient circle-and-bar design.
The masthead consists of the two green stripes, the gray bar, and the text within. Notice how the top green bar has a right-arc, while the lower part of the gray bar has a left-arc that blends into the gray column. Now, resize your browser window.
The logo stays the same size, but the masthead adjusts to fill the space. Please review the discussion and examples on our 
Standard Package or
Deluxe Package 
