If you've ever had to do a job interview or make a sales pitch, you're probably familiar with how uncomfortable it is to come up with a list of positive traits for you or your product. Here's a secret: it's just as uncomfortable for the listener. Instead, focus on what you (or what you're selling) can offer the person to make a better pitch.
As writer James Greig points out, all too often pitches are centred around the "Me" of a product or person. Your resume says "I'm great", the products you buy talk about how proud the company is of all the work they did on this new, amazing version that's only incrementally better than the last one at twice the price. This is a terrible way to pitch. Instead, try to identify a problem the person you're talking to is trying to solve, then demonstrate how you (or your product/service) are the solution to that problem:
In other words: to write better copy, think about the implicit reasons for using your product or service, not the explicit ones.
The first iPod wasn't marketed as "a 5GB MP3 player" (boring/techy) but as "1,000 songs in your pocket" (wow/that's cool).
Olark doesn't bill itself simply as "live chat" (meh), but as a way to "make your customer's happy" (win).
And it's not "LinkedIn: a social network for business" (yawn), it's "LinkedIn: Be great at what you do" (because who wouldn't want that?)
The more you can emphasise how you solve a legitimate (as opposed to invented) problem for your customer, the more likely you can sell them on it. Of course, the flip side to this is that there are some people you won't be able to sell because they don't actually need your service. This is fine. It's easier to retain someone who genuinely needs you than it is to force your services on someone who wasn't really into the service you provide in the first place.