Taking notes

Smart question;

I would jot down the following;
Married? Single? (if single, gender) Age group? Kids? Pets? Allergies? Type of work? Type of vacuum (because I sold vacuum cleaners), Type of lead (referral, cold call, past customer, from other salesperson). Had they bought from another in home salesperson before? (yes/no, what was it?)..

About the sale itself;
Objections raised,(and I would write out what they said), my answers (write out what I said), results (sale/no sale). Price I sold for.

Anything I said differently that they liked/disliked. Any new way I asked questions, and the results. What was said (by both of us) just before they bought. Any new order of the presentation, and the results.

This may take up one full written page on a Yellow Legal pad.

And I would study the notes every few months, looking to see patterns, and see what I could change to improve performance.

I found, for example;
If a wife was alone (husband wasn't there), they bought 2% of the time.

Both there, they bought 41% on Cold Calls, and about 80% on referrals.
If they had previously bought from another in home salesperson, there was better than a 90% chance, that they would buy from me.
Single men bought at the same rate as single women.
Teachers almost never bought.
If I gave the price up front, they were far more likely to pay full price.
Age made no difference. Kids made no difference. Pets made a sale maybe 10% more likely.
If they owned a water softener, they were far more likely to buy from me.
Everyone from another country, was more likely to buy, except one (No, I won't say which one)
Gay couples bought more often than straight couples.
I identified four ways to tell that they had bad credit, without asking.

I discovered that the single best investment of time when selling, was another closing question.

I discovered that by heavily qualifying them up front (almost never resulting in them not taking a look), I almost never needed more than one closing attempt.

Anything more salesy than, "Would you like one" was regarded as high pressure by teachers.

Nobody bought later, if I did the presentation.

Referrals from people who bought, gave me other people that would buy.
Referrals from non buyers were almost totally worthless.
The worst leads were registrations at Fairs.
The best leads were past buyers of mine, followed by referrals (If I worked the system well).

The more expensive the vacuum they had, the more likely they would buy mine.

And I found, through experimentation, the single most profitable price to sell at.

Of course, there is much more, but that's pretty much the notes I took. i also took notes on presentations I watched from other salespeople.