Advertising costs money so whenever something is "advertised" you're going to pay more unless the advertising generates enough business to get an economy of scale greater than the cost of advertising. Advertising makes a lot of sense when you have something with high capital costs but low per unit costs. (Think CPUs or software based businesses). When you're buying a service such as cleaning where most of the costs come from labour it's going to be difficult to generate an economy of scale great enough for advertising to pay for itself. In businesses with out great economies of scale the increased cost of advertising is going to be passed to the consumer.
You're always going to get a better rate on a service business by doing a little leg work yourself and cutting out the "middle man".