When a customer suggests I take a look at what their competitors are doing, my first instinct is to hit them over the head add that to the bottom of my Things list as it is so often a sign that a company is looking to follow their competitors or peers, rather than ask their own customers (existing or prospective) what their expectations of a site will be &mdash never a great start.

Not looking beyond a specific industry can miss out on a whole host of different ideas and influences. These influences might come from the magazine or newspaper that you read this morning, or the label on the smoothie than went with it. So why look at other sites from a sector at all? Not, I hope, for design inspiration.

I find it useful to study other peoples' approaches. I look for conventions that make sense because they might be familiar and so aid usability. I look for the depth and structure of information and how people are directed to a call-to-action. I never look to be inspired by a sector's aesthetic, but I do look for repetitive design trends or motifs, because I prefer to make something that (I hope) will be distinctive from them.

CannyBill suggested several sites that they thought warranted attention. Being the enlightened bunch they are, their suggestions were for background information and not for design direction.

Here is what was on their list, plus a few more (marked) that I thought rounded out the selection.

The Invoice Machine (site | Flickr screenshot)

WordPress.com * (site | Flickr screenshot)

FreeAgent (site | Flickr screenshot)

GoodBarry (site | Flickr screenshot)

FreshBooks (site | Flickr screenshot)

Freelance Total (site | Flickr screenshot)

MailChimp (site | Flickr screenshot)

Blinksale (site | Flickr screenshot)

Atebits (Tweetie) * (site | Flickr screenshot)

CampaignMonitor (site | Flickr screenshot)

At this point in the process, I looked at the first impressions that these home pages made. Some, in particular stand out. WordPress.com's layout is exquisitely distinctive, I never tire of Tim Van Damme's details on Atebits and Jon Hicks' clever illustration transforms MailChimp. On the other side of the coin, I was surprised to find just how may sites sported screen captures in their right-side column and other design motifs that seem to be common in the sector.

Basecamp (site | Flickr screenshot)

This list could never be complete without Basecamp and while I don't always enjoy the 37signals design aesthetic (personal taste), it's hard to find a flaw in their superbly crafted information and process. Judging by the examples that I looked at, designing a site that sells software is difficult without following in 37signals' footsteps or (in some cases) deliberately treading on its toes.