At the beginning, you will make less money when you build a list.
Ok, let's say you have a $37 product.
Let's compare two situations where we promote the $37 product, one as a One-Time Offer after a squeeze page signup, and the other with the sales page as the home page.
Let's put industry averages into this hypothetical experiment.
100 visitors (30% opt-in rate, although this can be easily 40% and above) => 30 subscribers => $0 in sales (only 30 people, albeit responsive people who have given you their email address, get to see your sales page)
Total sales per month => 18 ($666) - 30 people seeing your sales page everyday
100 visitors (2% conversion) => $74 in sales
Total sales per month => 60 ($2220)
So that's a deficit of $1554 in this 'worst case scenario' for squeeze pages.
So for the squeeze page model to make the same amount as the sales page model initially, it would need about 250 visitors for a 30% opt-in rate.
Let's continue our experiment...
After 6 months, at an average of 30 subscribers per day, you'll have about 4500-5000 subscribers (after unsubscribes). With proper email marketing techniques, you can make in excess of $500 for every email you send. If you send 4 promo emails a month, that's $2000 extra on top of your OTO sales.
Now we're generating $2666 on top of the OTO sales we're making. Now we're beating the sales page model by $446.
The bottom line: I'm not discounting the sales page model. It works if you build a list as well with it. Do note though that with a sales page you will have a lower signup rate (10% or less is not uncommon unless you use an immediate popup on the site).
The key is to build a list if you want to use the sales page model straight up.