I don't think the place is as much of an issue for me as the amount.
There have been times I got somewhere and bought something that was 75 cents or $1.50 and only then discovered NO CASH. I admit I felt a little sheepish pulling out a credit card for such a small purchase amount.
I have no shame in where I choose to use a credit card, regarless of purchase amount.
One of my cards is a Corporate card...you better believe I have charged $1.50 on that card if I was away on business. It's the best way to track expenses, and guarantee that my employer will not have to reimburse me money...they just pay the bill at the end of the month.
If I'm away on business and happened to go to McDonalds for lunch (although, not my first choice), I would absolutely put it on my corporate card!
If I saw someone using a credit card in a less-than-desirable location or for a super-small purchase, I would just assume it was someone on a business trip!
I use my credit cards for just about everything, except for maybe the <$3 purchases. I use my B of A Upromise MC for most purchases to earn bucks for my kids' future education, and use my AmEx at restaurants to get a 3% rebate. I don't have any qualms about using it anywhere. Of course, I don't patronize any places that would be called unseemly....
I go to an ATM only once every 2 months and pull out $200 for both me and my DW. That's how infrequently we use cash.
There is a very real reason why the term "cashless society" was coined. We are not quite there yet, or most are not. I am however. I never spend money, and I mean never. (I don't get colds and flu all the time either)
I don't like to get change. It ends up in containers for years. It is a nuisance to me.
I know categorically what I spend each month and I do use that info to tweak my habits.
Certainly there is no harm in purchasing with a product made for purchasing.
When I mentioned I tend to cringe a bit at using a CC for small amounts, like $1.50, this is because I understand the merchant has certain fees. Sometimes this includes a transaction fee which might be 30-40 cents, plus the discount fee.
So, if I make a $1.50 purchase and they incur a 35 cent transaction fee plus 2-3% discount fee (very likely if using reward cards), then this merchant has taken a real hit on the sale.
I always like to create win-win scenarios. I enjoy the convenience of credit cards. I enjoy the convenience and services of the merchants I shop. I want all to profit. Thus I kick myself when I find that I need to charge such a small amount.