£26 a customer is poor.
You should be averaging about £5 a lead or £10 a Conversion.
I've spent £3k total on my account and whilst I can't tell you how many customers exactly I've obtained its about 1000 leads so assume 500 customers.
to be fair it really comes down to the numbers so assumptions about your conversion rate isn't enough.
and assuming a 50% conversion rate is pretty incredible from this type of lead.
i;d be interested to really see what the numbers were if you do spend some time digging into them
also of course it comes down to the quality of the customer you're getting
we've all had the experience of canvassers getting lots of poor quality customers.
i find it hard to believe that a 50% conversion rate from facebook ads would be decent customers at the right price, expecting a regular service, etc etc etc
so what i would be interested to hear is the lifetime value of the customers you're getting from this marketing
i'd rather have a 10% conversion rate of quality customers than 50% conversion rate of messers and bad customers
but obv would be very interested to be convinced otherwise