You really could use many methods to run an SEO business
There is a problem debating this, most people on this forum are well versed in the ways of online business and to some extent SEO, although very few sit at the top of Google, not a dig just a fact. So the ideas discussed may seem to hold some merit but reality they don't work.
The reason they don't work....The average punter comes to an SEO provider because their site is under performing, of course they are interested in the clients I have provided services for, the techniques I use and the ranking of my own website, however their main question is always cost related. If they find my charges acceptable, most want to pass over the reigns and leave me to it and rightly so most have to spend their time running their own business.
A new client expects results and quickly, sort that out and the relationship prospers. If you can't they leave.
Introducing staged payments, PFP or any other scheme indicates I am untrustworthy, something that is certainly not the case. My lasted client, Jase dotwhat (dot) net signed up last week, he is a well educated 'techie' who asked for a free trial period, I said no and explained the terms of service, leaving him to decide, an hour to make his mind, paid a month in advance and I added his site to the pot. If I produce the goods he will stay a long term client, if I don't he will look elsewhere.
I believe simplification is a USP in SEO
It may be for you but for many businesses they need a bit more confidence before parting with hard cash up front.
I do not as long as trust is built by provable results but many small businesses will have a problem with parting with cash upfront.
When you place your business in a space that demands those terms , when any potential client can find several more companies that can do what you do without the same terms in about 5 minutes are you not placing your business in an difficult position?
I am sure you are aware that they are many , many good seo/sem firms and we are also aware that there are lots of crap ones.
What happens to your clients tomorrow if you are sick or worse you are run over, do you have a team as good as you, do your clients know what happens in that situation?
Just pointing out that it is very easy to have a system and think it is right, but all systems need reviewed on an ongoing basis.
Normal credit terms are not untrustworthy nor are stage payments , they are just normal business processes that exist and are used and when SEO/SEM act out with them it comes across as strange to experienced and serious business people and therefore raises questions.
I have today signed stage payment deals worth most SEO companies annual turnover that would not have been signed had the supplier wanted upfront payment.
You seem to be operating a business on a personal level which is fine if it suits you but if someone gave me a hour to decide on a project I would take the hour to stop laughing.