In starting a small software consultancy and figuring out how to market and present ourselves to the world...
Does anyone have any experience as to whether it is best to market yourself based on:
Which is the more effective way to sell yourself as a development team?
Software consultancy is a ridiculously competitive market; I don't want to scare you! but it's going to be tough.
The only reliable way to market and effectively present your company is to develop and advertise your USP (unique selling point), whatever it is.
I'm afraid it cannot be .NET development though; there are thousands of companies selling this expertise. However (I don't know the .NET environment) you can probably find niches inside the .NET market, for example you can advertise yourself as expert in the customisation of certain .NET-based products (lucene.net, umbraco f.i.).
As a general rule
I would start from where it has worked for you first -- build off your existing customers and why they chose you. Leverage the existing proven connection and play from there.
You need to find a unique value proposition to present yourself to the customer. Such a value proposition is not developed from the "inside out" but from the "outside in" meaning don't start with the product -- start with the client problem it solves -- the solution. Don't start with the technology platform -- start with the advantage your knowledge of that technology passes on to the client.
Look at how your target customer makes it's decisions. Talk to them, or look at how your competitor positions themselves to the target customer.
Of the three you mention I think that you will find the most traction by positioning yourself as a solution expert in a specific market segmentation that leverages your experience and skill with specific systems to delivers those solutions.
You should focus on the industries you have experience with. Think about it from the point of view of your customers.
They probably don't care what technology you use, might be slightly interested that you have built a similar type of system before but care a lot that you understand their industry and business.
Coders with technical skills are a dime a dozen. Coders who understand the business case and how to apply technology to serve the business are a lot rarer. THAT is something you can build a consultancy around.