Unless you are managing the application of the survey itself, you will be paying for the survey company's overhead and for the sample you are hoping to achieve. If you have adequate details about your users (sex/age/income), you can tailor your sample and target the minimum number of users until you assemble an effective sample.
Minimizing exposure to your survey:
- Saves you money from the survey company
- Preserves users' likelihood of participating in a survey in the future
- Minimizes the annoyance of a survey, which is distracting from the service you are providing the user
Pushing a survey at all distracts your end user, can compromise your brand (adds at least the complexity of "if I go to that site, I might get a survey thrown in my face"), and lends volatility to the experience overall; minimizing exposure to that possible variable in the users' experiences preserves the coherence of whatever narrative your users have in mind for when they visit your site.
A tertiary concern; surveys, particularly ones where you are looking for preferences and feedback about your product, can be a double-edged sword for the participant. They may feel some satisfaction at having had their concerns and opinions valued and considered. They may feel that their answers are not valued, however, if nothing changes or they feel there is no direct connection between investing their opinion and the site. Over-saturation of survey prompts may embattle that disenfranchisement, and distribute it among your users. Unused opinions have a way of inculcating a perception of a brand and environment. If you provide an ineffective way for leveraging those opinions, and fail to deliver, it erodes confidence.